diff --git a/frontend/app/player/common/ListWalker.ts b/frontend/app/player/common/ListWalker.ts
index ca3d409ac..61f93f8df 100644
--- a/frontend/app/player/common/ListWalker.ts
+++ b/frontend/app/player/common/ListWalker.ts
@@ -105,11 +105,11 @@ export default class ListWalker<T extends Timed> {
 			: null
 	}
 
-	/*
-		Returns last message with the time <= t.
-		Assumed that the current message is already handled so
-		if pointer doesn't cahnge <null> is returned.
-	*/
+	/**
+	 * @returns last message with the time <= t.
+	 * Assumed that the current message is already handled so
+	 * if pointer doesn't cahnge <null> is returned.
+	 */
 	moveGetLast(t: number, index?: number): T | null {
 		let key: string = "time"; //TODO
 		let val = t;
@@ -130,7 +130,13 @@ export default class ListWalker<T extends Timed> {
 		return changed ? this.list[ this.p - 1 ] : null;
 	}
 
-	async moveWait(t: number, callback: (msg: T) => Promise<any> | undefined): Promise<void> {
+	/**
+	 * Moves over the messages starting from the current+1 to the last one with the time <= t
+	 * applying callback on each of them
+	 * @param t - max message time to move to; will move & apply callback while msg.time <= t
+	 * @param callback - a callback to apply on each message passing by while moving
+	 */
+	moveApply(t: number, callback: (msg: T) => void): void {
 		// Applying only in increment order for now
 		if (t < this.timeNow) {
 			this.reset();
@@ -138,8 +144,7 @@ export default class ListWalker<T extends Timed> {
 
 		const list = this.list
 		while (list[this.p] && list[this.p].time <= t) {
-			const maybePromise = callback(this.list[ this.p++ ]);
-			if (maybePromise) { await maybePromise }
+			callback(this.list[ this.p++ ])
 		}
 	}
 
diff --git a/frontend/app/player/common/SimpleStore.ts b/frontend/app/player/common/SimpleStore.ts
index dd7e1ee7b..973fa4cb8 100644
--- a/frontend/app/player/common/SimpleStore.ts
+++ b/frontend/app/player/common/SimpleStore.ts
@@ -1,6 +1,5 @@
 import { Store } from './types'
 
-// (not a type)
 export default class SimpleSore<G, S=G> implements Store<G, S> {
   constructor(private state: G){}
   get(): G {
diff --git a/frontend/app/player/web/managers/DOM/DOMManager.ts b/frontend/app/player/web/managers/DOM/DOMManager.ts
index 8e0fb8b6b..f6291fa0a 100644
--- a/frontend/app/player/web/managers/DOM/DOMManager.ts
+++ b/frontend/app/player/web/managers/DOM/DOMManager.ts
@@ -9,40 +9,36 @@ import FocusManager from './FocusManager';
 import SelectionManager from './SelectionManager';
 import type { StyleElement } from './VirtualDOM';
 import {
-  PostponedStyleSheet,
+  OnloadStyleSheet,
   VDocument,
   VElement,
+  VHTMLElement,
   VNode,
   VShadowRoot,
-  VStyleElement,
   VText,
+  OnloadVRoot,
 } from './VirtualDOM';
 import { deleteRule, insertRule } from './safeCSSRules';
 
-type HTMLElementWithValue = HTMLInputElement | HTMLTextAreaElement | HTMLSelectElement;
 
-const IGNORED_ATTRS = [ "autocomplete" ];
-const ATTR_NAME_REGEXP = /([^\t\n\f \/>"'=]+)/; // regexp costs ~
-
-
-// TODO: filter out non-relevant  prefixes
-// function replaceCSSPrefixes(css: string) {
-//   return css
-//     .replace(/\-ms\-/g, "")
-//     .replace(/\-webkit\-/g, "")
-//     .replace(/\-moz\-/g, "")
-//     .replace(/\-webkit\-/g, "")
-// }
+function isStyleVElement(vElem: VElement): vElem is VElement & { node: StyleElement } {
+  return vElem.tagName.toLowerCase() === "style"
+}
 
+const IGNORED_ATTRS = [ "autocomplete" ]
+const ATTR_NAME_REGEXP = /([^\t\n\f \/>"'=]+)/
 
 export default class DOMManager extends ListWalker<Message> {
   private readonly vTexts: Map<number, VText> = new Map() // map vs object here?
   private readonly vElements: Map<number, VElement> = new Map()
-  private readonly vRoots: Map<number, VShadowRoot | VDocument> = new Map()
-  private styleSheets: Map<number, CSSStyleSheet> = new Map()
-  private ppStyleSheets: Map<number, PostponedStyleSheet> = new Map()
+  private readonly olVRoots: Map<number, OnloadVRoot> = new Map()
+  /** Constructed StyleSheets https://developer.mozilla.org/en-US/docs/Web/API/Document/adoptedStyleSheets
+   * as well as <style> tag owned StyleSheets
+   */
+  private olStyleSheets: Map<number, OnloadStyleSheet> = new Map()
+  /** @depreacted since tracker 4.0.2 Mapping by nodeID */
+  private olStyleSheetsDeprecated: Map<number, OnloadStyleSheet> = new Map()
   private stringDict: Record<number,string> = {}
-  private attrsBacktrack: Message[] = []
 
   private upperBodyId: number = -1;
   private nodeScrollManagers: Map<number, ListWalker<SetNodeScroll>> = new Map()
@@ -91,21 +87,20 @@ export default class DOMManager extends ListWalker<Message> {
     super.append(m)
   }
 
-  private removeBodyScroll(id: number, vn: VElement): void {
+  private removeBodyScroll(id: number, vElem: VElement): void {
     if (this.isMobile && this.upperBodyId === id) { // Need more type safety!
-      (vn.node as HTMLBodyElement).style.overflow = "hidden"
+      (vElem.node as HTMLBodyElement).style.overflow = "hidden"
     }
   }
 
-  // May be make it as a message on message add?
-  private removeAutocomplete(node: Element): boolean {
-    const tag = node.tagName
+  private removeAutocomplete(vElem: VElement): boolean {
+    const tag = vElem.tagName
     if ([ "FORM", "TEXTAREA", "SELECT" ].includes(tag)) {
-      node.setAttribute("autocomplete", "off");
+      vElem.setAttribute("autocomplete", "off");
       return true;
     }
     if (tag === "INPUT") {
-      node.setAttribute("autocomplete", "new-password");
+      vElem.setAttribute("autocomplete", "new-password");
       return true;
     }
     return false;
@@ -117,22 +112,24 @@ export default class DOMManager extends ListWalker<Message> {
       logger.error("Insert error. Node not found", id);
       return;
     }
-    const parent = this.vElements.get(parentID) || this.vRoots.get(parentID)
+    const parent = this.vElements.get(parentID) || this.olVRoots.get(parentID)
     if (!parent) {
-      logger.error("Insert error. Parent node not found", parentID, this.vElements, this.vRoots);
+      logger.error("Insert error. Parent vNode not found", parentID, this.vElements, this.olVRoots);
       return;
     }
 
-    const pNode = parent.node
-    if ((pNode instanceof HTMLStyleElement) &&  // TODO: correct ordering OR filter in tracker
-        pNode.sheet &&
-        pNode.sheet.cssRules &&
-        pNode.sheet.cssRules.length > 0 &&
-        pNode.innerText &&
-        pNode.innerText.trim().length === 0
-    ) {
-      logger.log("Trying to insert child to a style tag with virtual rules: ", parent, child);
-      return;
+    if (parent instanceof VElement && isStyleVElement(parent)) {
+      // TODO: if this ever happens? ; Maybe do not send empty TextNodes in tracker
+      const styleNode = parent.node
+      if (styleNode.sheet &&
+        styleNode.sheet.cssRules &&
+        styleNode.sheet.cssRules.length > 0 &&
+        styleNode.textContent &&
+        styleNode.textContent.trim().length === 0
+      ) {
+        logger.log("Trying to insert child to a style tag with virtual rules: ", parent, child);
+        return;
+      }
     }
 
     parent.insertChildAt(child, index)
@@ -143,25 +140,27 @@ export default class DOMManager extends ListWalker<Message> {
     const vn = this.vElements.get(msg.id)
     if (!vn) { logger.error("SetNodeAttribute: Node not found", msg); return }
 
-    if (vn.node.tagName === "INPUT" && name === "name") {
-      // Otherwise binds local autocomplete values (maybe should ignore on the tracker level)
+    if (vn.tagName === "INPUT" && name === "name") {
+      // Otherwise binds local autocomplete values (maybe should ignore on the tracker level?)
       return
     }
-    if (name === "href" && vn.node.tagName === "LINK") {
+    if (name === "href" && vn.tagName === "LINK") {
       // @ts-ignore  ?global ENV type   // It've been done on backend (remove after testing in saas)
       // if (value.startsWith(window.env.ASSETS_HOST || window.location.origin + '/assets')) {
       //   value = value.replace("?", "%3F");
       // }
       if (!value.startsWith("http")) {
+        /* blob:... value can happen here for some reason.
+         * which will result in that link being unable to load and having 4sec timeout in the below function.
+         */
         return
       }
-      // blob:... value can happen here for some reason.
-      // which will result in that link being unable to load and having 4sec timeout in the below function.
 
-      // TODO: check if node actually exists on the page, not just in memory
+      // TODOTODO: check if node actually exists on the page, not just in memory
       this.stylesManager.setStyleHandlers(vn.node as HTMLLinkElement, value);
     }
-    if (vn.node.namespaceURI === 'http://www.w3.org/2000/svg' && value.startsWith("url(")) {
+    if (vn.isSVG && value.startsWith("url(")) {
+      /* SVG shape ID-s for masks etc. Sometimes referred with the full-page url, which we don't have in replay */
       value = "url(#" + (value.split("#")[1] ||")")
     }
     vn.setAttribute(name, value)
@@ -169,12 +168,9 @@ export default class DOMManager extends ListWalker<Message> {
   }
 
   private applyMessage = (msg: Message): Promise<any> | undefined => {
-    let vn: VNode | undefined
-    let doc: Document | null
-    let styleSheet: CSSStyleSheet | PostponedStyleSheet | undefined
     switch (msg.tp) {
-      case MType.CreateDocument:
-        doc = this.screen.document;
+      case MType.CreateDocument: {
+        const doc = this.screen.document;
         if (!doc) {
           logger.error("No root iframe document found", msg, this.screen)
           return;
@@ -185,58 +181,51 @@ export default class DOMManager extends ListWalker<Message> {
         const fRoot = doc.documentElement;
         fRoot.innerText = '';
 
-        vn = new VElement(fRoot)
+        const vHTMLElement = new VHTMLElement(fRoot)
         this.vElements.clear()
-        this.vElements.set(0, vn)
-        const vDoc = new VDocument(doc)
-        vDoc.insertChildAt(vn, 0)
-        this.vRoots.clear()
-        this.vRoots.set(0, vDoc) // watchout: id==0 for both Document and documentElement
+        this.vElements.set(0, vHTMLElement)
+        const vDoc = OnloadVRoot.fromDocumentNode(doc)
+        vDoc.insertChildAt(vHTMLElement, 0)
+        this.olVRoots.clear()
+        this.olVRoots.set(0, vDoc) // watchout: id==0 for both Document and documentElement
         // this is done for the AdoptedCSS logic
-        // todo: start from 0-node (sync logic with tracker)
+        // Maybetodo: start Document as 0-node in tracker
         this.vTexts.clear()
         this.stylesManager.reset()
         this.stringDict = {}
         return
-      case MType.CreateTextNode:
-        vn = new VText()
-        this.vTexts.set(msg.id, vn)
+      }
+      case MType.CreateTextNode: {
+        const vText = new VText()
+        this.vTexts.set(msg.id, vText)
         this.insertNode(msg)
         return
-      case MType.CreateElementNode:
-        let element: Element
-        if (msg.svg) {
-          element = document.createElementNS('http://www.w3.org/2000/svg', msg.tag)
-        } else {
-          element = document.createElement(msg.tag)
+      }
+      case MType.CreateElementNode: {
+        const vElem = new VElement(msg.tag, msg.svg)
+        if (['STYLE', 'style', 'LINK'].includes(msg.tag)) {
+          vElem.prioritized = true
         }
-        if (msg.tag === "STYLE" || msg.tag === "style") {
-          vn = new VStyleElement(element as StyleElement)
-        } else {
-          vn = new VElement(element)
-        }
-        this.vElements.set(msg.id, vn)
+        this.vElements.set(msg.id, vElem)
         this.insertNode(msg)
-        this.removeBodyScroll(msg.id, vn)
-        this.removeAutocomplete(element)
-        if (['STYLE', 'style', 'LINK'].includes(msg.tag)) { // Styles in priority
-          vn.enforceInsertion()
-        }
+        this.removeBodyScroll(msg.id, vElem)
+        this.removeAutocomplete(vElem)
         return
+      }
       case MType.MoveNode:
-        this.insertNode(msg);
+        this.insertNode(msg)
         return
-      case MType.RemoveNode:
-        vn = this.vElements.get(msg.id) || this.vTexts.get(msg.id)
-        if (!vn) { logger.error("RemoveNode: Node not found", msg); return }
-        if (!vn.parentNode) { logger.error("RemoveNode: Parent node not found", msg); return }
-        vn.parentNode.removeChild(vn)
+      case MType.RemoveNode: {
+        const vChild = this.vElements.get(msg.id) || this.vTexts.get(msg.id)
+        if (!vChild) { logger.error("RemoveNode: Node not found", msg); return }
+        if (!vChild.parentNode) { logger.error("RemoveNode: Parent node not found", msg); return }
+        vChild.parentNode.removeChild(vChild)
         this.vElements.delete(msg.id)
         this.vTexts.delete(msg.id)
         return
+      }
       case MType.SetNodeAttribute:
-        if (msg.name === 'href') this.attrsBacktrack.push(msg)
-        else this.setNodeAttribute(msg)
+        this.setNodeAttribute(msg)
         return
       case MType.StringDict:
         this.stringDict[msg.key] = msg.value
@@ -245,24 +234,22 @@ export default class DOMManager extends ListWalker<Message> {
         this.stringDict[msg.nameKey] === undefined && logger.error("No dictionary key for msg 'name': ", msg)
         this.stringDict[msg.valueKey] === undefined && logger.error("No dictionary key for msg 'value': ", msg)
         if (this.stringDict[msg.nameKey] === undefined || this.stringDict[msg.valueKey] === undefined ) { return }
-        if (this.stringDict[msg.nameKey] === 'href') this.attrsBacktrack.push(msg)
-        else {
-          this.setNodeAttribute({
-            id: msg.id,
-            name: this.stringDict[msg.nameKey],
-            value: this.stringDict[msg.valueKey],
-          })
-        }
+        this.setNodeAttribute({
+          id: msg.id,
+          name: this.stringDict[msg.nameKey],
+          value: this.stringDict[msg.valueKey],
+        })
         return
-      case MType.RemoveNodeAttribute:
-          vn = this.vElements.get(msg.id)
-          if (!vn) { logger.error("RemoveNodeAttribute: Node not found", msg); return }
-          vn.removeAttribute(msg.name)
+      case MType.RemoveNodeAttribute: {
+        const vElem = this.vElements.get(msg.id)
+        if (!vElem) { logger.error("RemoveNodeAttribute: Node not found", msg); return }
+        vElem.removeAttribute(msg.name)
         return
-      case MType.SetInputValue:
-        vn = this.vElements.get(msg.id)
-        if (!vn) { logger.error("SetInoputValue: Node not found", msg); return }
-        const nodeWithValue = vn.node
+      }
+      case MType.SetInputValue: {
+        const vElem = this.vElements.get(msg.id)
+        if (!vElem) { logger.error("SetInoputValue: Node not found", msg); return }
+        const nodeWithValue = vElem.node
         if (!(nodeWithValue instanceof HTMLInputElement
             || nodeWithValue instanceof HTMLTextAreaElement
             || nodeWithValue instanceof HTMLSelectElement)
@@ -271,222 +258,183 @@ export default class DOMManager extends ListWalker<Message> {
           return
         }
         const val = msg.mask > 0 ? '*'.repeat(msg.mask) : msg.value
-        doc = this.screen.document
+        const doc = this.screen.document
         if (doc && nodeWithValue === doc.activeElement) {
           // For the case of Remote Control
           nodeWithValue.onblur = () => { nodeWithValue.value = val }
           return
         }
-        nodeWithValue.value = val
+        nodeWithValue.value = val // Maybe make special VInputValueElement type for lazy value update
         return
-      case MType.SetInputChecked:
-        vn = this.vElements.get(msg.id)
-        if (!vn) { logger.error("SetInputChecked: Node not found", msg); return }
-        (vn.node as HTMLInputElement).checked = msg.checked
+      }
+      case MType.SetInputChecked: {
+        const vElem = this.vElements.get(msg.id)
+        if (!vElem) { logger.error("SetInputChecked: Node not found", msg); return }
+        (vElem.node as HTMLInputElement).checked = msg.checked // Maybe make special VCheckableElement type for lazy checking
         return
+      }
       case MType.SetNodeData:
-      case MType.SetCssData: // mbtodo: remove  css transitions when timeflow is not natural (on jumps)
-        vn = this.vTexts.get(msg.id)
-        if (!vn) { logger.error("SetCssData: Node not found", msg); return }
-        vn.setData(msg.data)
-        if (msg.tp === MType.SetCssData) { // Styles in priority  (do we need inlines as well?)
-          vn.applyChanges()
-        }
+      case MType.SetCssData: {
+        const vText = this.vTexts.get(msg.id)
+        if (!vText) { logger.error("SetNodeData/SetCssData: Node not found", msg); return }
+        vText.setData(msg.data)
         return
+      }
 
-      // @deprecated since 4.0.2 in favor of adopted_ss_insert/delete_rule + add_owner as being common case for StyleSheets
-      case MType.CssInsertRule:
-        vn = this.vElements.get(msg.id)
-        if (!vn) { logger.error("CssInsertRule: Node not found", msg); return }
-        if (!(vn instanceof VStyleElement)) {
-          logger.warn("Non-style node in CSS rules message (or sheet is null)", msg, vn);
-          return
+      /** @deprecated 
+       * since 4.0.2 in favor of AdoptedSsInsertRule/DeleteRule + AdoptedSsAddOwner as a common case for StyleSheets
+       */
+      case MType.CssInsertRule: {
+        let styleSheet = this.olStyleSheetsDeprecated.get(msg.id)
+        if (!styleSheet) {
+          const vElem = this.vElements.get(msg.id)
+          if (!vElem) { logger.error("CssInsertRule: Node not found", msg); return }
+          if (!isStyleVElement(vElem)) { logger.error("CssInsertRule: Non-style element", msg); return }
+          styleSheet = OnloadStyleSheet.fromStyleElement(vElem.node)
+          this.olStyleSheetsDeprecated.set(msg.id, styleSheet)
         }
-        vn.onStyleSheet(sheet => insertRule(sheet, msg))
+        styleSheet.insertRule(msg.rule, msg.index)
         return
-      case MType.CssDeleteRule:
-        vn = this.vElements.get(msg.id)
-        if (!vn) { logger.error("CssDeleteRule: Node not found", msg); return }
-        if (!(vn instanceof VStyleElement)) {
-          logger.warn("Non-style node in CSS rules message (or sheet is null)", msg, vn);
-          return
-        }
-        vn.onStyleSheet(sheet => deleteRule(sheet, msg))
+      }
+      case MType.CssDeleteRule: {
+        const styleSheet = this.olStyleSheetsDeprecated.get(msg.id)
+        if (!styleSheet) { logger.error("CssDeleteRule: StyleSheet was not created", msg); return }
+        styleSheet.deleteRule(msg.index)
         return
-      // end @deprecated
-
-      case MType.CreateIFrameDocument:
-        vn = this.vElements.get(msg.frameID)
-        if (!vn) { logger.error("CreateIFrameDocument: Node not found", msg); return }
-        vn.enforceInsertion()
-        const host = vn.node
-        if (host instanceof HTMLIFrameElement) {
-          const doc = host.contentDocument
-          if (!doc) {
-            logger.warn("No default iframe doc", msg, host)
-            return
-          }
-
-          const vDoc = new VDocument(doc)
-          this.vRoots.set(msg.id, vDoc)
-          return;
-        } else if (host instanceof Element) { // shadow DOM
-          try {
-            const shadowRoot = host.attachShadow({ mode: 'open' })
-            vn = new VShadowRoot(shadowRoot)
-            this.vRoots.set(msg.id, vn)
-          } catch(e) {
-            logger.warn("Can not attach shadow dom", e, msg)
-          }
-        } else {
-          logger.warn("Context message host is not Element", msg)
-        }
+      }
+      /* end @deprecated */
+      case MType.CreateIFrameDocument: {
+        const vElem = this.vElements.get(msg.frameID)
+        if (!vElem) { logger.error("CreateIFrameDocument: Node not found", msg); return }
+        const vRoot = OnloadVRoot.fromVElement(vElem)
+        vRoot.catch(e => logger.warn(e, msg))
+        this.olVRoots.set(msg.id, vRoot)
         return
-      case MType.AdoptedSsInsertRule:
-        styleSheet = this.styleSheets.get(msg.sheetID) || this.ppStyleSheets.get(msg.sheetID)
+      }
+      case MType.AdoptedSsInsertRule: {
+        const styleSheet = this.olStyleSheets.get(msg.sheetID)
         if (!styleSheet) {
           logger.warn("No stylesheet was created for ", msg)
           return
         }
         insertRule(styleSheet, msg)
         return
-      case MType.AdoptedSsDeleteRule:
-        styleSheet = this.styleSheets.get(msg.sheetID) || this.ppStyleSheets.get(msg.sheetID)
+      }
+      case MType.AdoptedSsDeleteRule: {
+        const styleSheet = this.olStyleSheets.get(msg.sheetID)
         if (!styleSheet) {
           logger.warn("No stylesheet was created for ", msg)
           return
         }
         deleteRule(styleSheet, msg)
         return
-
-      case MType.AdoptedSsReplace:
-        styleSheet = this.styleSheets.get(msg.sheetID)
+      }
+      case MType.AdoptedSsReplace: {
+        const styleSheet = this.olStyleSheets.get(msg.sheetID)
         if (!styleSheet) {
           logger.warn("No stylesheet was created for ", msg)
           return
         }
-        // @ts-ignore
+        // @ts-ignore (configure ts with recent WebaAPI)
         styleSheet.replaceSync(msg.text)
         return
-      case MType.AdoptedSsAddOwner:
-        vn = this.vRoots.get(msg.id)
-        if (!vn) {
-          // non-constructed case
-          vn = this.vElements.get(msg.id)
-          if (!vn) { logger.error("AdoptedSsAddOwner: Node not found", msg); return }
-          if (!(vn instanceof VStyleElement)) { logger.error("Non-style owner", msg); return }
-          this.ppStyleSheets.set(msg.sheetID, new PostponedStyleSheet(vn.node))
-          return
-        }
-        styleSheet = this.styleSheets.get(msg.sheetID)
-        if (!styleSheet) {
-          let context: typeof globalThis
-          const rootNode = vn.node
-          if (rootNode.nodeType === Node.DOCUMENT_NODE) {
-            context = (rootNode as Document).defaultView
-          } else {
-            context = (rootNode as ShadowRoot).ownerDocument.defaultView
-          }
-          styleSheet = new context.CSSStyleSheet()
-          this.styleSheets.set(msg.sheetID, styleSheet)
-        }
-        //@ts-ignore
-        vn.node.adoptedStyleSheets = [...vn.node.adoptedStyleSheets, styleSheet]
-        return
-      case MType.AdoptedSsRemoveOwner:
-        styleSheet = this.styleSheets.get(msg.sheetID)
-        if (!styleSheet) {
-          logger.warn("No stylesheet was created for ", msg)
-          return
-        }
-        vn = this.vRoots.get(msg.id)
-        if (!vn) { logger.error("AdoptedSsRemoveOwner: Node not found", msg); return }
-        //@ts-ignore
-        vn.node.adoptedStyleSheets = [...vn.node.adoptedStyleSheets].filter(s => s !== styleSheet)
-        return
-      case MType.LoadFontFace:
-        vn = this.vRoots.get(msg.parentID)
-        if (!vn) { logger.error("LoadFontFace: Node not found", msg); return }
-        if (vn instanceof VShadowRoot) { logger.error(`Node ${vn} expected to be a Document`, msg); return }
-        let descr: Object
-        try {
-          descr = JSON.parse(msg.descriptors)
-          descr = typeof descr === 'object' ? descr : undefined
-        } catch {
-          logger.warn("Can't parse font-face descriptors: ", msg)
-        }
-        const ff = new FontFace(msg.family, msg.source, descr)
-        vn.node.fonts.add(ff)
-        return ff.load()
-    }
-  }
-
-  applyBacktrack(msg: Message) {
-    // @ts-ignore
-    const target = this.vElements.get(msg.id)
-    if (!target) {
-      return
-    }
-
-    switch (msg.tp) {
-      case MType.SetNodeAttribute: {
-        this.setNodeAttribute(msg)
-        return
       }
-      case MType.SetNodeAttributeDict: {
-        this.stringDict[msg.nameKey] === undefined && logger.error("No dictionary key for msg 'name': ", msg)
-        this.stringDict[msg.valueKey] === undefined && logger.error("No dictionary key for msg 'value': ", msg)
-        if (this.stringDict[msg.nameKey] === undefined || this.stringDict[msg.valueKey] === undefined) {
+      case MType.AdoptedSsAddOwner: {
+        const vRoot = this.olVRoots.get(msg.id)
+        if (!vRoot) {
+          /* <style> tag case */
+          const vElem = this.vElements.get(msg.id)
+          if (!vElem) { logger.error("AdoptedSsAddOwner: Node not found", msg); return }
+          if (!isStyleVElement(vElem)) { logger.error("Non-style owner", msg); return }
+          this.olStyleSheets.set(msg.sheetID, OnloadStyleSheet.fromStyleElement(vElem.node))
           return
         }
-        this.setNodeAttribute({
-          id: msg.id,
-          name: this.stringDict[msg.nameKey],
-          value: this.stringDict[msg.valueKey],
+        /* Constructed StyleSheet case */
+        let olStyleSheet = this.olStyleSheets.get(msg.sheetID)
+        if (!olStyleSheet) {
+          olStyleSheet = OnloadStyleSheet.fromVRootContext(vRoot)
+          this.olStyleSheets.set(msg.sheetID, olStyleSheet)
+        }
+        olStyleSheet.whenReady(styleSheet => {
+          vRoot.onNode(node => {
+            // @ts-ignore
+            node.adoptedStyleSheets = [...node.adoptedStyleSheets, styleSheet]
+          })
         })
-        return;
+        return
+      }
+      case MType.AdoptedSsRemoveOwner: {
+        const olStyleSheet = this.olStyleSheets.get(msg.sheetID)
+        if (!olStyleSheet) {
+          logger.warn("AdoptedSsRemoveOwner: No stylesheet was created for ", msg)
+          return
+        }
+        const vRoot = this.olVRoots.get(msg.id)
+        if (!vRoot) { logger.error("AdoptedSsRemoveOwner: Owner node not found", msg); return }
+        olStyleSheet.whenReady(styleSheet => {
+          vRoot.onNode(node => {
+            // @ts-ignore
+            node.adoptedStyleSheets = [...vRoot.node.adoptedStyleSheets].filter(s => s !== styleSheet)
+          })
+        })
+        return
+      }
+      case MType.LoadFontFace: {
+        const vRoot = this.olVRoots.get(msg.parentID)
+        if (!vRoot) { logger.error("LoadFontFace: Node not found", msg); return }
+        vRoot.whenReady(vNode => {
+          if (vNode instanceof VShadowRoot) { logger.error(`Node ${vNode} expected to be a Document`, msg); return }
+          let descr: Object | undefined
+          try {
+            descr = JSON.parse(msg.descriptors)
+            descr = typeof descr === 'object' ? descr : undefined
+          } catch {
+            logger.warn("Can't parse font-face descriptors: ", msg)
+          }
+          const ff = new FontFace(msg.family, msg.source, descr)
+          vNode.node.fonts.add(ff)
+          ff.load() // TODOTODO: wait for this one in StylesManager in a common way with styles
+        })
+        return
       }
     }
   }
 
+  /**
+   * Moves and applies all the messages from the current (or from the beginning, if t < current.time) 
+   * to the one with msg.time >= `t`
+   * 
+   * This function autoresets pointer if necessary (better name?)
+   * 
+   * @returns Promise that fulfulls when necessary changes get applied 
+   *   (the async part exists mostly due to styles loading)
+   */
   async moveReady(t: number): Promise<void> {
-    // MBTODO (back jump optimisation):
-    //    - store intemediate virtual dom state
-    //    - cancel previous moveReady tasks (is it possible?) if new timestamp is less
-    // This function autoresets pointer if necessary (better name?)
+    this.moveApply(t, this.applyMessage)
 
-    /**
-     * Basically just skipping all set attribute with attrs being "href" if user is 'jumping'
-     * to the other point of replay to save time on NOT downloading any resources before the dom tree changes
-     * are applied, so it won't try to download and then cancel when node is created in msg N and removed in msg N+2
-     * which produces weird bug when asset is cached (10-25ms delay)
-     * */
-    // http://0.0.0.0:3333/5/session/8452905874437457
-    // 70 iframe, 8 create element - STYLE tag
-    await this.moveWait(t, this.applyMessage)
-
-    this.attrsBacktrack.forEach(msg => {
-      this.applyBacktrack(msg)
-    })
-    this.attrsBacktrack = []
-
-    this.vRoots.forEach(rt => rt.applyChanges()) // MBTODO (optimisation): affected set
+    this.olVRoots.forEach(rt => rt.applyChanges())
     // Thinkabout (read): css preload
     // What if we go back before it is ready? We'll have two handlres?
     return this.stylesManager.moveReady(t).then(() => {
-      // Apply focus
+      /* Waiting for styles to be applied first */
+      /* Applying focus */
       this.focusManager.move(t)
+      /* Applying text selections */
       this.selectionManager.move(t)
-      // Apply all scrolls after the styles got applied
+      /* Applying all scrolls */
       this.nodeScrollManagers.forEach(manager => {
         const msg = manager.moveGetLast(t)
         if (msg) {
-          let vNode: VNode
-          if (vNode = this.vElements.get(msg.id)) {
-            vNode.node.scrollLeft = msg.x
-            vNode.node.scrollTop = msg.y
-          } else if ((vNode = this.vRoots.get(msg.id)) && vNode instanceof VDocument){
-            vNode.node.defaultView?.scrollTo(msg.x, msg.y)
+          let scrollVHost: VElement | OnloadVRoot | undefined
+          if (scrollVHost = this.vElements.get(msg.id)) {
+            scrollVHost.node.scrollLeft = msg.x
+            scrollVHost.node.scrollTop = msg.y
+          } else if ((scrollVHost = this.olVRoots.get(msg.id))) {
+            scrollVHost.whenReady(vNode => {
+              if (vNode instanceof VDocument) {
+                vNode.node.defaultView?.scrollTo(msg.x, msg.y)
+              }
+            })
           }
         }
       })
diff --git a/frontend/app/player/web/managers/DOM/VirtualDOM.ts b/frontend/app/player/web/managers/DOM/VirtualDOM.ts
index a528ae658..e43d2be38 100644
--- a/frontend/app/player/web/managers/DOM/VirtualDOM.ts
+++ b/frontend/app/player/web/managers/DOM/VirtualDOM.ts
@@ -1,69 +1,119 @@
-type VChild = VElement | VText
-
-export type VNode = VDocument | VShadowRoot | VElement | VText
-
 import { insertRule, deleteRule } from './safeCSSRules';
 
-abstract class VParent {
-	abstract node: Node | null
+
+type Callback<T> = (o: T) => void
+
+/**
+ * Virtual Node base class.
+ * Implements common abstract methods and lazy node creation logic.
+ * 
+ * @privateRemarks
+ * Would be better to export type-only, but didn't find a nice way to do that.
+ */
+export abstract class VNode<T extends Node = Node> {
+	protected abstract createNode(): T
+	private _node: T | null
+	/**
+	 * JS DOM Node getter with lazy node creation
+	 * 
+	 * @returns underneath JS DOM Node
+	 * @remarks should not be called unless the real node is required since creation might be expensive
+	 * 	It is better to use `onNode` callback applicator unless in the `applyChanges` implementation
+	 */
+	get node(): T {
+		if (!this._node) {
+			const node = this._node = this.createNode()
+			this.nodeCallbacks.forEach(cb => cb(node))
+			this.nodeCallbacks = []
+		}
+		return this._node
+	}
+	private nodeCallbacks: Callback<T>[] = []
+	/**
+	 * Lazy Node callback applicator
+	 *
+	 * @param callback - Callback that fires on existing JS DOM Node instantly if it exists
+	 * or whenever it gets created. Call sequence is concerned.
+	 */
+	onNode(callback: Callback<T>) {
+		if (this._node) {
+			callback(this._node)
+			return
+		}
+		this.nodeCallbacks.push(callback)
+	}
+	/**
+	 * Abstract method, should be implemented by the actual classes
+	 * It is supposed to apply virtual changes into the actual DOM
+	 */
+	public abstract applyChanges(): void
+}
+
+
+type VChild = VElement | VText
+abstract class VParent<T extends Node = Node> extends VNode<T>{
 	protected children: VChild[] = []
-	private insertedChildren: Set<VChild> = new Set()
+	private childrenToMount: Set<VChild> = new Set()
 
 	insertChildAt(child: VChild, index: number) {
 		if (child.parentNode) {
 			child.parentNode.removeChild(child)
 		}
 		this.children.splice(index, 0, child)
-		this.insertedChildren.add(child)
+		this.childrenToMount.add(child)
 		child.parentNode = this
 	}
 
 	removeChild(child: VChild) {
 		this.children = this.children.filter(ch => ch !== child)
-		this.insertedChildren.delete(child)
+		this.childrenToMount.delete(child)
 		child.parentNode = null
 	}
 
-	applyChanges() {
-		const node = this.node
-		if (!node) {
-			// log err
-			console.error("No node found", this)
-			return
-		}
-		// inserting
+	protected mountChildren(shouldInsert?: (child: VChild) => boolean) {
+		let nextMounted: VChild | null = null
 		for (let i = this.children.length-1; i >= 0; i--) {
 			const child = this.children[i]
-			child.applyChanges()
-			if (this.insertedChildren.has(child)) {
-				const nextVSibling = this.children[i+1]
-				node.insertBefore(child.node, nextVSibling ? nextVSibling.node : null)
+			if (this.childrenToMount.has(child) &&
+				(!shouldInsert || shouldInsert(child)) // is there a better way of not-knowing about subclass logic on prioritized insertion?
+			) {
+				this.node.insertBefore(child.node, nextMounted ? nextMounted.node : null)
+				this.childrenToMount.delete(child)
+			}
+			if (!this.childrenToMount.has(child)) {
+				nextMounted = child
 			}
 		}
-		this.insertedChildren.clear()
-		// removing
+	}
+
+	applyChanges() {
+		/* Building a sub-trees first (in-memory for non-mounted children) */
+		this.children.forEach(child => child.applyChanges())
+		/* Inserting */
+		this.mountChildren()
+		if (this.childrenToMount.size !== 0) {
+			console.error("VParent: Something went wrong with children insertion")
+		}
+		/* Removing in-between */
+		const node = this.node
 		const realChildren = node.childNodes
 		for(let j = 0; j < this.children.length; j++) {
 			while (realChildren[j] !== this.children[j].node) {
 				node.removeChild(realChildren[j])
 			}
 		}
-		// removing rest
+		/* Removing tail */
 		while(realChildren.length > this.children.length) {
-			node.removeChild(node.lastChild)
+			node.removeChild(node.lastChild as Node) /* realChildren.length > this.children.length >= 0 so it is not null */
 		}
 	}
 }
 
-export class VDocument extends VParent {
-	constructor(public readonly node: Document) { super() }
+export class VDocument extends VParent<Document> {
+	constructor(protected readonly createNode: () => Document) { super() }
 	applyChanges() {
 		if (this.children.length > 1) {
-			// log err
-		}
-		if (!this.node) {
-			// iframe not mounted yet
-			return
+			console.error("VDocument expected to have a single child.", this)
 		}
 		const child = this.children[0]
 		if (!child) { return }
@@ -75,14 +125,22 @@ export class VDocument extends VParent {
 	}
 }
 
-export class VShadowRoot extends VParent {
-	constructor(public readonly node: ShadowRoot) { super() }
+export class VShadowRoot extends VParent<ShadowRoot> {
+	constructor(protected readonly createNode: () => ShadowRoot) { super() }
 }
 
-export class VElement extends VParent {
-	parentNode: VParent | null = null
+export type VRoot = VDocument | VShadowRoot
+
+export class VElement extends VParent<Element> {
+	parentNode: VParent | null = null /** Should be modified only by he parent itself */
 	private newAttributes: Map<string, string | false> = new Map()
-	constructor(public readonly node: Element) { super() }
+
+	constructor(readonly tagName: string, readonly isSVG = false) { super() }
+	protected createNode() {
+		return this.isSVG
+			? document.createElementNS('http://www.w3.org/2000/svg', this.tagName)
+			: document.createElement(this.tagName)
+	}
 	setAttribute(name: string, value: string) {
 		this.newAttributes.set(name, value)
 	}
@@ -90,18 +148,7 @@ export class VElement extends VParent {
 		this.newAttributes.set(name, false)
 	}
 
-	// mbtodo: priority insertion instead.
-	// rn this is for styles that should be inserted as prior, 
-	// otherwise it will show visual styling lag if there is a transition CSS property)
-	enforceInsertion() {
-		let vNode: VElement = this
-		while (vNode.parentNode instanceof VElement) {
-			vNode = vNode.parentNode
-		}
-		(vNode.parentNode || vNode).applyChanges()
-	}
-
-	applyChanges() {
+	private applyAttributeChanges() { // "changes" -> "updates" ?
 		this.newAttributes.forEach((value, key) => {
 			if (value === false) {
 				this.node.removeAttribute(key)
@@ -114,88 +161,57 @@ export class VElement extends VParent {
 			}
 		})
 		this.newAttributes.clear()
+	}
+
+	applyChanges() {
+		this.prioritized && this.applyPrioritizedChanges()
+		this.applyAttributeChanges()
 		super.applyChanges()
 	}
-}
 
-
-type StyleSheetCallback = (s: CSSStyleSheet) => void
-export type StyleElement = HTMLStyleElement | SVGStyleElement
-
-// @deprecated TODO: remove in favor of PostponedStyleSheet
-export class VStyleElement extends VElement {
-	private loaded = false
-	private stylesheetCallbacks: StyleSheetCallback[] = []
-	constructor(public readonly node: StyleElement) { 
-		super(node)  // Is it compiled correctly or with 2 node assignments?
-		node.onload = () => {
-		  const sheet = node.sheet
-		  if (sheet) {
-		    this.stylesheetCallbacks.forEach(cb => cb(sheet))
-		    this.stylesheetCallbacks = []
-		  } else {
-		    // console.warn("Style onload: sheet is null") ?
-				// sometimes logs sheet ton of errors for some reason
-		  }
-		  this.loaded = true
-		}
-	}
-
-	onStyleSheet(cb: StyleSheetCallback) {
-		if (this.loaded) {
-			if (!this.node.sheet) {
-				console.warn("Style tag is loaded, but sheet is null")
-				return
+	/** Insertion Prioritization
+	 * Made for styles that should be inserted as prior, 
+	 * otherwise it will show visual styling lag if there is a transition CSS property)
+	 */
+	prioritized = false
+	insertChildAt(child: VChild, index: number) {
+		super.insertChildAt(child, index)
+		/* Bubble prioritization */
+		if (child instanceof VElement && child.prioritized) {
+			let parent: VParent | null = this
+			while (parent instanceof VElement && !parent.prioritized) {
+				parent.prioritized = true
+				parent = parent.parentNode
 			}
-			cb(this.node.sheet)
-		} else {
-		  this.stylesheetCallbacks.push(cb)
 		}
 	}
-}
-
-
-export class PostponedStyleSheet {
-	private loaded = false
-	private stylesheetCallbacks: StyleSheetCallback[] = []
-
-	constructor(private readonly node: StyleElement) {
-		node.onload = () => {
-		  const sheet = node.sheet
-		  if (sheet) {
-		    this.stylesheetCallbacks.forEach(cb => cb(sheet))
-		    this.stylesheetCallbacks = []
-		  } else {
-		    console.warn("Style node onload: sheet is null")
-		  }
-		  this.loaded = true
-		}
-	}
-
-	private applyCallback(cb: StyleSheetCallback) {
-		if (this.loaded) {
-			if (!this.node.sheet) {
-				console.warn("Style tag is loaded, but sheet is null")
-				return
+	private applyPrioritizedChanges() {
+		this.children.forEach(child => {
+			if (child instanceof VText) {
+				child.applyChanges()
+			} else if (child.prioritized) {
+				/* Update prioritized VElement-s */
+				child.applyPrioritizedChanges()
+				child.applyAttributeChanges()
 			}
-			cb(this.node.sheet)
-		} else {
-		  this.stylesheetCallbacks.push(cb)
-		}
-	}
-
-	insertRule(rule: string, index: number) {
-		this.applyCallback(s => insertRule(s, { rule, index }))
-	}
-
-	deleteRule(index: number) {
-		this.applyCallback(s => deleteRule(s, { index }))
+		})
+		this.mountChildren(child => child instanceof VText || child.prioritized)
 	}
 }
 
-export class VText {
+export class VHTMLElement extends VElement {
+	constructor(node: HTMLElement) {
+		super("HTML", false)
+		this.createNode = () => node
+	}
+}
+
+export class VText extends VNode<Text> {
 	parentNode: VParent | null = null
-	constructor(public readonly node: Text = new Text()) {}
+	protected createNode() {
+		return new Text()
+	}
+
 	private data: string = ""
 	private changed: boolean = false
 	setData(data: string) {
@@ -210,3 +226,112 @@ export class VText {
 	}
 }
 
+class PromiseQueue<T> {
+	constructor(private promise: Promise<T>) {}
+	/**
+	 * Call sequence is concerned.
+	 */
+	// Doing this with callbacks list instead might be more efficient (but more wordy). TODO: research
+	whenReady(cb: Callback<T>) {
+		this.promise = this.promise.then(vRoot => {
+			cb(vRoot)
+			return vRoot
+		})
+	}
+	catch(cb: Parameters<Promise<T>['catch']>[0]) {
+		this.promise.catch(cb)
+	}
+}
+
+/**
+ * VRoot wrapper that allows to defer all the API calls till the moment
+ * when VNode CAN be created (for example, on <iframe> mount&load)
+ */
+export class OnloadVRoot extends PromiseQueue<VRoot> {
+	static fromDocumentNode(doc: Document): OnloadVRoot {
+		return new OnloadVRoot(Promise.resolve(new VDocument(() => doc)))
+	}
+	static fromVElement(vElem: VElement): OnloadVRoot {
+		return new OnloadVRoot(new Promise((resolve, reject) => {
+			vElem.onNode(host => {
+				if (host instanceof HTMLIFrameElement) {
+					/* IFrame case: creating Document */
+					const doc = host.contentDocument
+					if (doc) {
+						resolve(new VDocument(() => doc))
+					} else {
+						host.addEventListener('load', () => {
+							const doc = host.contentDocument
+							if (doc) {
+								resolve(new VDocument(() => doc))
+							} else {
+								reject("No default Document found on iframe load") // Send `host` for logging as well
+							}
+						})
+					}
+				} else {
+				/* ShadowDom case */
+					try {
+						const shadowRoot = host.attachShadow({ mode: 'open' })
+						resolve(new VShadowRoot(() => shadowRoot))
+					} catch(e) {
+						reject(e) // "Can not attach shadow dom"
+					}
+				}
+			})
+		}))
+	}
+	onNode(cb: Callback<Document | ShadowRoot>) {
+		this.whenReady(vRoot => vRoot.onNode(cb))
+	}
+	applyChanges() {
+		this.whenReady(vRoot => vRoot.applyChanges())
+	}
+	insertChildAt(...args: Parameters<VParent['insertChildAt']>) {
+		this.whenReady(vRoot => vRoot.insertChildAt(...args))
+	}
+}
+
+export type StyleElement = HTMLStyleElement | SVGStyleElement
+
+/**
+ * CSSStyleSheet wrapper that collects all the insertRule/deleteRule calls 
+ * and then applies them when the sheet is ready
+ */
+export class OnloadStyleSheet extends PromiseQueue<CSSStyleSheet> {
+	static fromStyleElement(node: StyleElement) {
+		return new OnloadStyleSheet(new Promise((resolve, reject) => {
+			node.addEventListener("load", () => {
+				const sheet = node.sheet
+				if (sheet) {
+					resolve(sheet)
+				} else {
+					reject("Style node onload: sheet is null")
+				}
+			})
+		}))
+	}
+	static fromVRootContext(vRoot: OnloadVRoot) {
+		return new OnloadStyleSheet(new Promise((resolve, reject) => 
+			vRoot.onNode(node => {
+				let context: typeof globalThis | null
+				if (node instanceof Document) {
+					context = node.defaultView
+				} else {
+					context = node.ownerDocument.defaultView
+				}
+				if (!context) { reject("Root node default view not found"); return }
+				/* a StyleSheet from another Window context won't work */
+				resolve(new context.CSSStyleSheet())
+			})
+		))
+	}
+
+	insertRule(rule: string, index: number) {
+		this.whenReady(s => insertRule(s, { rule, index }))
+	}
+
+	deleteRule(index: number) {
+		this.whenReady(s => deleteRule(s, { index }))
+	}
+}
diff --git a/frontend/app/player/web/messages/rewriter/rewriteMessage.ts b/frontend/app/player/web/messages/rewriter/rewriteMessage.ts
index d488c8362..b64817e64 100644
--- a/frontend/app/player/web/messages/rewriter/rewriteMessage.ts
+++ b/frontend/app/player/web/messages/rewriter/rewriteMessage.ts
@@ -15,6 +15,18 @@ import { MType } from '../raw.gen'
 import { resolveURL, resolveCSS } from './urlResolve'
 import { HOVER_CLASSNAME, FOCUS_CLASSNAME } from './constants'
 
+/* maybetodo:  filter out non-relevant  prefixes in CSS-rules. 
+   They might cause an error in console, but not sure if it breaks the replay.
+   (research required)
+*/
+// function replaceCSSPrefixes(css: string) {
+//   return css
+//     .replace(/\-ms\-/g, "")
+//     .replace(/\-webkit\-/g, "")
+//     .replace(/\-moz\-/g, "")
+//     .replace(/\-webkit\-/g, "")
+// }
+
 const HOVER_SELECTOR = `.${HOVER_CLASSNAME}`
 const FOCUS_SELECTOR = `.${FOCUS_CLASSNAME}`
 export function replaceCSSPseudoclasses(cssText: string): string {