diff --git a/background/key_mappings.ts b/background/key_mappings.ts
index 4c863e7f3..bf1185689 100644
--- a/background/key_mappings.ts
+++ b/background/key_mappings.ts
@@ -914,9 +914,10 @@ updateHooks_.keyMappings = (value: string | null): void => {
   updatesInKeyFSM = !!oldFSM && f(keyFSM_) !== f(oldFSM),
   updatesInMappedKeys = oldMappedKeys ? !curMapped || f(oldMappedKeys) !== f(curMapped) : !!oldFSM && !!curMapped;
   (updatesInMappedKeys || updatesInKeyFSM) && settings_.broadcast_({
-    N: kBgReq.keyFSM, m: mappedKeyRegistry_, t: mappedKeyTypes_, k: updatesInKeyFSM ? keyFSM_ : null
+    N: kBgReq.keyFSM, m: mappedKeyRegistry_, t: mappedKeyTypes_, k: updatesInKeyFSM ? keyFSM_ : null,
+    v: BgUtils_.nextConfUpdate(0)
   });
   if (oldOmniMapKeys ? !curOmniMapped || f(oldOmniMapKeys) !== f(curOmniMapped) : curOmniMapped) {
-    settings_.broadcastOmni_({ N: kBgReq.omni_updateOptions, d: { m: curOmniMapped } })
+    settings_.broadcastOmniConf_({ m: curOmniMapped })
   }
 };
diff --git a/background/page_handlers.ts b/background/page_handlers.ts
index d35cc8c73..2c42f4074 100644
--- a/background/page_handlers.ts
+++ b/background/page_handlers.ts
@@ -1,10 +1,12 @@
 import {
   contentPayload_, evalVimiumUrl_, keyFSM_, keyToCommandMap_, mappedKeyRegistry_, newTabUrls_, restoreSettings_,
   CONST_, settingsCache_, shownHash_, substitute_, framesForTab_, curTabId_, extAllowList_, OnChrome, reqH_, OnEdge,
-  storageCache_, os_, framesForOmni_, updateHooks_, Origin2_, CurCVer_
+  storageCache_, os_, framesForOmni_, updateHooks_, Origin2_, CurCVer_, omniConfVer_
 } from "./store"
 import { deferPromise_, protocolRe_, safeObj_ } from "./utils"
-import { browserWebNav_, browser_, getCurTab, getTabUrl, Q_, runContentScriptsOn_, runtimeError_, tabsCreate, tabsGet } from "./browser"
+import {
+  browserWebNav_, browser_, getCurTab, getTabUrl, Q_, runContentScriptsOn_, runtimeError_, tabsCreate, tabsGet
+} from "./browser"
 import { convertToUrl_, lastUrlType_, reformatURL_ } from "./normalize_urls"
 import { findUrlInText_, parseSearchEngines_ } from "./parse_urls"
 import * as settings_ from "./settings"
@@ -270,7 +272,7 @@ const pageRequestHandlers_: {
   /** kPgReq.updateOmniPayload: */ ({ key, val }, port): void => {
     const tabId = port && port.s && port.s.tabId_ || curTabId_
     const omniPort = framesForOmni_.find(i => i.s.tabId_ === tabId)
-    omniPort && omniPort.postMessage({ N: kBgReq.omni_updateOptions, d: { [key]: val } })
+    omniPort && omniPort.postMessage({ N: kBgReq.omni_updateOptions, d: { [key]: val }, v: omniConfVer_ })
   },
   /** kPgReq.saveToSyncAtOnce: */ (): void => {
     settingsCache_.vimSync && updateHooks_.vimSync!(true, "vimSync")
diff --git a/background/ports.ts b/background/ports.ts
index 311b288f9..83afd078c 100644
--- a/background/ports.ts
+++ b/background/ports.ts
@@ -2,7 +2,7 @@ import {
   needIcon_, cPort, set_cPort, reqH_, contentPayload_, omniPayload_, innerCSS_, extAllowList_, framesForTab_, findCSS_,
   framesForOmni_, getNextFakeTabId, curTabId_, vomnibarPage_f, OnChrome, CurCVer_, OnEdge, setIcon_, lastKeptTabId_,
   keyFSM_, mappedKeyRegistry_, CONST_, mappedKeyTypes_, recencyForTab_, setTeeTask_, OnFirefox, UseZhLang_, blank_,
-  set_lastKeptTabId_
+  set_lastKeptTabId_, omniConfVer_, contentConfVer_
 } from "./store"
 import { asyncIter_, deferPromise_, getOmniSecret_, isNotPriviledged, keys_ } from "./utils"
 import {
@@ -123,10 +123,12 @@ export const OnConnect = (port: Frames.Port, type: PortType): void => {
     /*#__NOINLINE__*/ _recoverStates(ref, port, type)
   } else {
     port.postMessage<kBgReq.init>(type & PortType.confInherited ? {
-      N: kBgReq.init, c: null as never as SettingsNS.FrontendSettingCache, d: isInactive, f: flags, p: passKeys
-    } satisfies Omit<Req.bg<kBgReq.init>, keyof BgReq[kBgReq.keyFSM]> as Req.bg<kBgReq.init> : {
+      N: kBgReq.init, c: null as never as SettingsNS.FrontendSettingCache, d: isInactive, f: flags, p: passKeys,
+      v: contentConfVer_
+    } satisfies Omit<Req.bg<kBgReq.init>, keyof Omit<BgReq[kBgReq.keyFSM], keyof ConfVersionReq>> as Req.bg<kBgReq.init>
+    : {
       N: kBgReq.init, c: contentPayload_, d: isInactive, f: flags,
-      k: keyFSM_!, m: mappedKeyRegistry_, p: passKeys, t: mappedKeyTypes_
+      k: keyFSM_!, m: mappedKeyRegistry_, p: passKeys, t: mappedKeyTypes_, v: contentConfVer_
     })
     if (isInactive) {
       port.disconnect()
@@ -207,8 +209,14 @@ const _onOmniConnect = (port: Frames.Port, type: PortType, isOmniUrl: boolean):
       if (!OnChrome) { (port as Frames.BrowserPort).sender.tab = null as never }
       port.onDisconnect.addListener(/*#__NOINLINE__*/ onOmniDisconnect)
       port.onMessage.addListener(/*#__NOINLINE__*/ onMessage)
-      type & PortType.reconnect ||
-      port.postMessage({ N: kBgReq.omni_init, l: omniPayload_, s: getOmniSecret_(false) })
+      if (type & PortType.reconnect) {
+        const oldConfVer = type >> PortType.OFFSET_SETTINGS
+        if (oldConfVer !== omniConfVer_) {
+          port.postMessage({ N: kBgReq.omni_updateOptions, d: omniPayload_, v: omniConfVer_ })
+        }
+      } else {
+        port.postMessage({ N: kBgReq.omni_init, l: omniPayload_, s: getOmniSecret_(false), v: omniConfVer_ })
+      }
       return
     }
   } else if (port.s.tabId_ < 0 // e.g.: inside a sidebar on MS Edge
@@ -699,7 +707,11 @@ const _recoverStates = (frames: Frames.Frames | undefined, port: Port, type: Por
       : (type & PortType.hasCSS) && Frames.Flags.hasCSS
   frames || refreshPorts_({ cur_: port, top_: null, ports_: [], lock_: null, flags_: Frames.Flags.HadIFrames }, 0)
   let flag = type as Frames.Flags
-  if (!(type & PortType.refreshInBatch)) {
+  if (type & PortType.refreshInBatch) { /* empty */ }
+  else if ((type >> PortType.OFFSET_SETTINGS) !== contentConfVer_
+      && !(frames && frames.flags_ & Frames.Flags.MASK_UPDATES)) {
+    flag = Frames.Flags.MASK_UPDATES
+  } else {
     if (!(type & PortType.hasFocus) // frame is not focused - on refreshing ports of inactive tabs
         || !frames || !(frames.flags_ & Frames.Flags.ResReleased)) { // no old data to sync
       return
@@ -708,11 +720,11 @@ const _recoverStates = (frames: Frames.Frames | undefined, port: Port, type: Por
     if (flag & Frames.Flags.HadIFrames || port.s.frameId_) { refreshPorts_(frames, 0) }
   }
   if (flag & Frames.Flags.SettingsUpdated) {
-    port.postMessage({ N: kBgReq.settingsUpdate, d: contentPayload_ })
+    port.postMessage({ N: kBgReq.settingsUpdate, d: contentPayload_, v: contentConfVer_ })
   }
   if (flag & Frames.Flags.KeyMappingsUpdated) {
     port.postMessage({ N: kBgReq.keyFSM, m: mappedKeyRegistry_, t: mappedKeyTypes_
-        , k: flag & Frames.Flags.KeyFSMUpdated ? keyFSM_ : null })
+        , k: flag & Frames.Flags.KeyFSMUpdated ? keyFSM_ : null, v: contentConfVer_ })
   }
   if (flag & Frames.Flags.CssUpdated && port.s.flags_ & Frames.Flags.hasCSS) {
     (port.s.flags_ satisfies Frames.Flags) |= Frames.Flags.hasFindCSS
diff --git a/background/settings.ts b/background/settings.ts
index 156b3a528..721ee0305 100644
--- a/background/settings.ts
+++ b/background/settings.ts
@@ -2,9 +2,9 @@ import {
   contentPayload_, extAllowList_, newTabUrls_, omniPayload_, OnChrome, OnEdge, OnFirefox, framesForOmni_, sync_, IsEdg_,
   settingsCache_, bgIniting_, set_bgIniting_, CurCVer_, CONST_, OnOther_, onInit_, storageCache_, searchEngines_,
   set_hasEmptyLocalStorage_, set_newTabUrl_f, newTabUrl_f, set_vomnibarPage_f, updateHooks_,set_CurFFVer_, UseZhLang_,
-  CurFFVer_, set_os_, os_
+  CurFFVer_, set_os_, os_, contentConfVer_
 } from "./store"
-import { asyncIter_, nextTick_, safeObj_ } from "./utils"
+import { asyncIter_, nextTick_, safeObj_, nextConfUpdate } from "./utils"
 import { browser_, normalizeExtOrigin_, Qs_ } from "./browser"
 import { convertToUrl_, reformatURL_ } from "./normalize_urls"
 import { parseSearchEngines_ } from "./parse_urls"
@@ -162,7 +162,8 @@ export const broadcast_ = <K extends kBgReq.settingsUpdate | kBgReq.url | kBgReq
 
 const _BroadcastSettingsUpdates = <K extends keyof BgReq> (
       request: K extends kBgReq.settingsUpdate ? SettingsUpdateMsg : Req.bg<K>): void => {
-    if (request.N === kBgReq.settingsUpdate && !request.d) {
+    const reqName = request.N
+    if (reqName === kBgReq.settingsUpdate && !(request.d as typeof request.d | null)) {
       const obj = newSettingsToBroadcast_!
       const d: BgReq[kBgReq.settingsUpdate]["d"] = (request as Req.bg<kBgReq.settingsUpdate>).d = {}
       for (const key of obj) {
@@ -170,19 +171,25 @@ const _BroadcastSettingsUpdates = <K extends keyof BgReq> (
       }
       newSettingsToBroadcast_ = null
     }
-    asyncIterFrames_(request.N === kBgReq.url ? Frames.Flags.UrlUpdated
-          : request.N === kBgReq.keyFSM ? Frames.Flags.KeyMappingsUpdated | (request.k ? Frames.Flags.KeyFSMUpdated : 0)
+    const needConfVer = reqName === kBgReq.keyFSM || kBgReq.settingsUpdate
+    asyncIterFrames_(reqName === kBgReq.url ? Frames.Flags.UrlUpdated
+          : reqName === kBgReq.keyFSM ? Frames.Flags.KeyMappingsUpdated | (request.k ? Frames.Flags.KeyFSMUpdated : 0)
           : Frames.Flags.SettingsUpdated
         , (frames: Frames.Frames): void => {
+      needConfVer && ((request as Req.bg<kBgReq.keyFSM | kBgReq.settingsUpdate>).v = contentConfVer_)
       for (const port of frames.ports_) {
         port.postMessage(request as Req.baseBg<K> as Req.bg<K>)
       }
     })
 }
 
-export const broadcastOmni_ = <K extends ValidBgVomnibarReq> (request: Req.bg<K>): void => {
+export const broadcastOmniConf_ = (payload: BgVomnibarSpecialReq[kBgReq.omni_updateOptions]["d"]
+    , excluded?: Port): void => {
+  const msg: Req.bg<kBgReq.omni_updateOptions> = { N: kBgReq.omni_updateOptions, d: payload, v: nextConfUpdate(1) }
   asyncIter_(framesForOmni_.slice(0), (frame): number => {
-    framesForOmni_.includes(frame) && frame.postMessage(request)
+    framesForOmni_.includes(frame) && frame.postMessage(frame !== excluded ? msg : {
+      N: kBgReq.omni_updateOptions, d: {}, v: msg.v
+    })
     return 1
   })
 }
@@ -252,7 +259,7 @@ Object.assign<typeof updateHooks_, { [key in SettingsNS.DeclaredUpdateHooks]: Se
     grabBackFocus (value: SettingsWithDefaults["grabBackFocus"]): void { contentPayload_.g = value },
     keyLayout (value): void {
       omniPayload_.l = contentPayload_.l
-      broadcastOmni_({ N: kBgReq.omni_updateOptions, d: { l: contentPayload_.l } })
+      broadcastOmniConf_({ l: contentPayload_.l })
       if (needToUpgradeSettings_ & 1 && !(value & kKeyLayout.fromOld)) {
         const hasInLocal = needToUpgradeSettings_ & 2
         needToUpgradeSettings_ &= ~(1 | 2)
diff --git a/background/store.ts b/background/store.ts
index daa388c5e..e4ba38d96 100644
--- a/background/store.ts
+++ b/background/store.ts
@@ -65,6 +65,8 @@ export const omniPayload_ = {
   c: "", i: 0, l: 0, m: null, n: 0, s: "", t: ""
 } satisfies SettingsNS.DeclaredVomnibarPayload as SettingsNS.VomnibarPayload
 export const vomnibarBgOptions_ = { actions: [] as string[] }
+export let contentConfVer_ = 0
+export let omniConfVer_ = 0
 export let omniStyleOverridden_ = false
 export let findCSS_: FindCSS
 export let innerCSS_: string
@@ -190,6 +192,8 @@ export const set_onInit_ = (_newInit: typeof onInit_): void => { onInit_ = _newI
 export const set_iconData_ = (_newIconData: typeof iconData_): void => { iconData_ = _newIconData }
 export const set_hasGroupPermission_ff_ = (_newAllowed: boolean | 0): void => { hasGroupPermission_ff_ = _newAllowed }
 export const set_lastKeptTabId_ = (_newKeptTabId: number): void => { lastKeptTabId_ = _newKeptTabId }
+export const set_contentConfVer_ = (_newContConfVer: number): number => { return contentConfVer_ = _newContConfVer }
+export const set_omniConfVer_ = (_newOmniConfVer: number): number => { return omniConfVer_ = _newOmniConfVer }
 
 export const set_reqH_ = (_newRH: BackendHandlersNS.FgRequestHandlers): void => { reqH_ = _newRH }
 export const set_bgC_ = (_newBgC: typeof bgC_): void => { bgC_ = _newBgC }
diff --git a/background/tools.ts b/background/tools.ts
index 6b1e42107..fbe955127 100644
--- a/background/tools.ts
+++ b/background/tools.ts
@@ -762,10 +762,10 @@ updateHooks_.vomnibarOptions = (options: SettingsNS.BackendSettings["vomnibarOpt
     MediaWatcher_.update_(MediaNS.kName.PrefersReduceMotion, 1)
     MediaWatcher_.update_(MediaNS.kName.PrefersColorScheme, 1)
   }
-  settings_.broadcastOmni_({ N: kBgReq.omni_updateOptions, d: {
+  settings_.broadcastOmniConf_({
     n: maxMatches,
     i: queryInterval,
     s: sizes,
     t: payload.t
-  } })
+  })
 }
diff --git a/background/ui_css.ts b/background/ui_css.ts
index 0351184a9..b328478a0 100644
--- a/background/ui_css.ts
+++ b/background/ui_css.ts
@@ -1,11 +1,11 @@
 import {
   findCSS_, innerCSS_, omniPayload_, set_findCSS_, set_innerCSS_, CurCVer_, CurFFVer_, IsEdg_, omniStyleOverridden_,
   OnChrome, OnEdge, OnFirefox, isHighContrast_ff_, set_isHighContrast_ff_, bgIniting_, CONST_, set_helpDialogData_,
-  framesForOmni_, settingsCache_, set_omniStyleOverridden_, updateHooks_, storageCache_, installation_
+  settingsCache_, set_omniStyleOverridden_, updateHooks_, storageCache_, installation_, contentConfVer_
 } from "./store"
-import { asyncIter_, fetchFile_, spacesRe_ } from "./utils"
+import { fetchFile_, nextConfUpdate, spacesRe_ } from "./utils"
 import { getFindCSS_cr_, set_getFindCSS_cr_ } from "./browser"
-import { ready_, broadcastOmni_, postUpdate_, setInLocal_ } from "./settings"
+import { ready_, broadcastOmniConf_, postUpdate_, setInLocal_ } from "./settings"
 import { asyncIterFrames_ } from "./ports"
 
 export declare const enum MergeAction {
@@ -208,6 +208,7 @@ export const mergeCSS = (css2Str: string, action: MergeAction | "userDefinedCss"
   setInLocal_(O, omni2 || null)
   reloadCSS_(MergeAction.readFromCache, newInnerCSS)
   if (action !== MergeAction.readFromCache && action !== MergeAction.rebuildWhenInit) {
+    nextConfUpdate(0)
     asyncIterFrames_(Frames.Flags.CssUpdated, (frames: Frames.Frames): void => {
         for (const port of frames.ports_) {
           const flags = port.s.flags_
@@ -216,10 +217,11 @@ export const mergeCSS = (css2Str: string, action: MergeAction | "userDefinedCss"
               N: kBgReq.showHUD, H: innerCSS_,
               f: flags & Frames.Flags.hasFindCSS ? OnChrome ? getFindCSS_cr_!(port.s) : findCSS_ : void 0
             })
+            port.postMessage({ N: kBgReq.settingsUpdate, d: {}, v: contentConfVer_ })
           }
         }
     })
-    broadcastOmni_({ N: kBgReq.omni_updateOptions, d: { c: omniPayload_.c } })
+    broadcastOmniConf_({ c: omniPayload_.c })
   }
 }
 
@@ -240,11 +242,7 @@ export const setOmniStyle_ = (req: FgReq[kFgReq.setOmniStyle], port?: Port): voi
   }
   if (styles === curStyles) { return }
   omniPayload_.t = styles
-  const request2: Req.bg<kBgReq.omni_updateOptions> = { N: kBgReq.omni_updateOptions, d: { t: styles } }
-  asyncIter_(framesForOmni_.slice(0), (frame): number => {
-    frame !== port && framesForOmni_.includes(frame) && frame.postMessage(request2)
-    return 1
-  })
+  broadcastOmniConf_({ t: styles }, port)
 }
 
 OnChrome && set_getFindCSS_cr_(((sender: Frames.Sender): FindCSS => {
diff --git a/background/utils.ts b/background/utils.ts
index ae0a7cb72..a7e243c56 100644
--- a/background/utils.ts
+++ b/background/utils.ts
@@ -1,4 +1,7 @@
-import { CurCVer_, CurFFVer_, framesForTab_, OnChrome, OnEdge, OnFirefox } from "./store"
+import {
+  contentConfVer_, CurCVer_, CurFFVer_, framesForTab_, omniConfVer_, OnChrome, OnEdge, OnFirefox, set_contentConfVer_,
+  set_omniConfVer_
+} from "./store"
 
 export const spacesRe_ = <RegExpG & RegExpSearchable<0>> /\s+/g
 export const protocolRe_ = <RegExpOne> /^[a-z][\+\-\.\da-z]+:\/\//
@@ -486,3 +489,9 @@ export const splitWhenKeepExpressions = (src: string, sep: string): string[] =>
   results.push(src.slice(lastInd))
   return results
 }
+
+export const nextConfUpdate = (useOmni: 0 | 1): number => {
+  let version = useOmni ? omniConfVer_ : contentConfVer_
+  version = ((version + 1) & 0xfff) || 1
+  return useOmni ? set_omniConfVer_(version) : set_contentConfVer_(version)
+}
diff --git a/content/port.ts b/content/port.ts
index b357a415d..fe178dfe5 100644
--- a/content/port.ts
+++ b/content/port.ts
@@ -1,6 +1,6 @@
 import {
   injector, safer, timeout_, isAlive_, isTop, set_i18n_getMsg, locHref, OnEdge, OnChrome, OnFirefox, isTY, fgCache,
-  interval_, setupTimerFunc_cr, noRAF_old_cr_, runtime_ff, isIFrameInAbout_, isLocked_, inherited_, chromeVer_
+  interval_, setupTimerFunc_cr, noRAF_old_cr_, runtime_ff, isIFrameInAbout_, isLocked_, inherited_, chromeVer_, confVersion
 } from "../lib/utils"
 import { suppressTail_ } from "../lib/keyboard_utils"
 import { docHasFocus_, rAF_ } from "../lib/dom_utils"
@@ -88,7 +88,8 @@ export const runtimeConnect = (function (this: void, extraFlags?: number): void
       : PortType.reconnect | extraFlags! | PortType.hasCSS * <number> <boolean | number> !!style_ui,
   name = (PortType.isTop === 1 ? <number> <boolean | number> isTop : PortType.isTop * <number> <number | boolean> isTop)
       | PortType.aboutIframe * <number> <number | boolean> isIFrameInAbout_ | onceFreezed | status
-      | PortType.hasFocus * <number> <number | boolean> docHasFocus_(),
+      | PortType.hasFocus * <number> <number | boolean> docHasFocus_()
+      | (confVersion << PortType.OFFSET_SETTINGS),
   data = { name: injector ? injector.$h(name) : OnEdge ? name + PortNameEnum.Delimiter + locHref() : "" + name },
   connect = (OnFirefox ? runtime_ff! : api.runtime).connect
   port_ = (injector ? connect(injector.id, data) : connect(data)) as ContentNS.Port
diff --git a/content/request_handlers.ts b/content/request_handlers.ts
index 998784d7e..930f14eaf 100644
--- a/content/request_handlers.ts
+++ b/content/request_handlers.ts
@@ -3,7 +3,7 @@ import {
   keydownEvents_, set_chromeVer_, set_clickable_, set_fgCache, set_isLocked_, OnChrome, OnFirefox, safeCall, recordLog,
   set_isEnabled_, set_onWndFocus, onWndFocus, timeout_, safer, set_os_, safeObj, set_keydownEvents_, setupEventListener,
   interval_, getTime, vApi, clearInterval_, locHref, set_firefoxVer_, firefoxVer_, os_, isAsContent, isIFrameInAbout_,
-  OnEdge, inherited_, clearTimeout_, setupTimerFunc_cr_mv3, set_weakRef_ff, weakRef_ff, deref_
+  OnEdge, inherited_, clearTimeout_, setupTimerFunc_cr_mv3, set_weakRef_ff, weakRef_ff, deref_, set_confVersion
 } from "../lib/utils"
 import { set_keyIdCorrectionOffset_old_cr_, handler_stack, suppressTail_ } from "../lib/keyboard_utils"
 import {
@@ -166,7 +166,7 @@ set_requestHandlers([
   },
   /* kBgReq.msg: */ onPortRes_,
   /* kBgReq.eval: */ evalIfOK,
-  /* kBgReq.settingsUpdate: */ ({ d: delta }: BgReq[kBgReq.settingsUpdate]): void => {
+  /* kBgReq.settingsUpdate: */ ({ d: delta, v: newConfVersion }: BgReq[kBgReq.settingsUpdate]): void => {
     type Keys = keyof typeof delta;
     safer(delta);
     for (const i in delta) {
@@ -175,6 +175,7 @@ set_requestHandlers([
       (i2 in fgCache) && delete safer(fgCache)[i2]
     }
     delta.d != null && hud_box && toggleClass_s(hud_box, "D", !!delta.d)
+    newConfVersion && set_confVersion(newConfVersion)
   },
   /* kBgReq.focusFrame: */ (req: BgReq[kBgReq.focusFrame]): void => {
     // Note: .c, .S are ensured to exist
@@ -202,6 +203,7 @@ set_requestHandlers([
     set_mapKeyTypes(request.t)
     set_mappedKeys(request.m)
     mappedKeys && safer(mappedKeys)
+    set_confVersion(request.v)
     esc!(HandlerResult.Nothing) // so that passNextKey#normal refreshes nextKeys to the new keyFSM
   },
   /* kBgReq.execute: */ function<O extends keyof CmdOptions> (request: BaseExecute<CmdOptions[O], O>): void {
diff --git a/front/vomnibar.ts b/front/vomnibar.ts
index f4677451d..6b6784f5e 100644
--- a/front/vomnibar.ts
+++ b/front/vomnibar.ts
@@ -1286,6 +1286,7 @@ var VCID_: string | undefined = VCID_ || "", VHost_: string | undefined = VHost_
       n = sizes.length > 3 ? +sizes[3] : 0
       Vomnibar_.panelWidth_ = M(0.3, m(n || VomnibarNS.PixelData.WindowSizeX, 0.95));
     }
+    VPort_._confVersion = response.v
   },
   OnWndFocus_ (this: void, event: Event): void {
     const a = Vomnibar_, byCode = a.codeFocusTime_ && performance.now() - a.codeFocusTime_ < 120,
@@ -1895,6 +1896,7 @@ VUtils_ = {
 },
 VPort_ = {
   _port: null as FgPort | null,
+  _confVersion: 0,
   postToOwner_: null as never as <K extends keyof VomnibarNS.FReq> (this: void
       , msg: VomnibarNS.FReq[K] & VomnibarNS.Msg<K>) => void | 1,
   post_<K extends keyof FgReq> (request: FgReq[K] & Req.baseFg<K>): void {
@@ -1915,7 +1917,7 @@ VPort_ = {
     name === kBgReq.omni_updateOptions ? Vomnibar_.updateOptions_(response) :
     name === kBgReq.omni_refresh ? !Vomnibar_.isActive_ && response.d ? Vomnibar_.OnUnload_()
         : Build.MV3 ? (VPort_._port!.disconnect(), VPort_.connect_(PortType.omnibar | PortType.reconnect)) : 0 :
-    name === kBgReq.injectorRun ? 0 :
+    name === kBgReq.injectorRun || name === kBgReq.showHUD ? 0 :
     0;
   },
   _OnOwnerMessage ({ data: data }: { data: VomnibarNS.CReq[keyof VomnibarNS.CReq] }): void {
@@ -1928,6 +1930,7 @@ VPort_ = {
   },
   _ClearPort (this: void): void { VPort_._port = null; },
   connect_ (type: PortType): FgPort {
+    type |= VPort_._confVersion << PortType.OFFSET_SETTINGS
     const data = { name: VCID_ ? PortNameEnum.Prefix + type + (PortNameEnum.Delimiter + BuildStr.Commit)
         : Build.BTypes === BrowserType.Edge as number
           || Build.BTypes & BrowserType.Edge && !!(window as {} as {StyleMedia: unknown}).StyleMedia
@@ -2011,7 +2014,7 @@ if (Build.BTypes === BrowserType.Chrome as number ? false : !(Build.BTypes & Bro
     }
     location.href = "about:blank"
   }, 700)
-  Vomnibar_.secret_ = function (this: void, {l: payload, s: secret}): void {
+  Vomnibar_.secret_ = function (this: void, { l: payload, s: secret, v: confVersion }): void {
     Vomnibar_.secret_ = null;
     if (!secret) { // see https://github.com/philc/vimium/issues/3832
       _sec = "2"; unsafeMsg.length = 0
@@ -2034,7 +2037,7 @@ if (Build.BTypes === BrowserType.Chrome as number ? false : !(Build.BTypes & Bro
     }
     if (Build.OS & (Build.OS - 1)) { Vomnibar_.os_ = payload.o }
     Vomnibar_.styles_ = payload.t;
-    Vomnibar_.updateOptions_({ N: kBgReq.omni_updateOptions, d: payload })
+    Vomnibar_.updateOptions_({ N: kBgReq.omni_updateOptions, d: payload, v: confVersion })
     _sec = secret;
     for (const i of unsafeMsg) {
       if (i[0] === secret) {
diff --git a/lib/utils.ts b/lib/utils.ts
index 08a288b97..bf8a5d028 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -66,6 +66,9 @@ export function set_noRAF_old_cr_ (_newNoRAF: BOOL): void { noRAF_old_cr_ = _new
 export let fgCache: OnlyEnsureItemsNonNull<SettingsNS.FrontendSettingCache>
 export function set_fgCache (_newCache: SettingsNS.FrontendSettingCache): void { fgCache = _newCache as typeof fgCache }
 
+export let confVersion = 0
+export function set_confVersion (_newConfVer: number): void { confVersion = _newConfVer }
+
 export let inherited_: 0 | PortType.confInherited = 0
 export function set_inherited_ (_newInherited: typeof inherited_): void { inherited_ = _newInherited }
 
diff --git a/typings/messages.d.ts b/typings/messages.d.ts
index 30ac1532f..6e0bdfc71 100644
--- a/typings/messages.d.ts
+++ b/typings/messages.d.ts
@@ -88,8 +88,8 @@ declare const enum kBgReq {
   init = START, reset, injectorRun, url, msg, eval,
   settingsUpdate, focusFrame, exitGrab, keyFSM, execute,
   showHUD, count, queryForRunKey, suppressForAWhile, refreshPort,
-  OMNI_MIN = 42,
-  omni_init = OMNI_MIN, omni_omni, omni_parsed, omni_returnFocus,
+  COMMON_OMNI_MIN = 42, // there're also injectorRun and showHUD
+  omni_init = COMMON_OMNI_MIN, omni_omni, omni_parsed, omni_returnFocus,
   omni_toggleStyle, omni_updateOptions, omni_refresh, omni_runTeeTask,
   END = "END", // without it, TypeScript will report errors for number indexes
 }
@@ -109,6 +109,8 @@ declare const enum kFgReq {
   command = "command", id = "id", shortcut = "shortcut", focus = "focus", tip = "tip",
 }
 
+interface ConfVersionReq { /** configuration version */ v: number }
+
 interface BgReq {
   [kBgReq.init]: {
     /** flags */ f: Frames.Flags;
@@ -118,7 +120,7 @@ interface BgReq {
     /** mappedKeys */ m: SafeDict<string> | null;
     /** keyFSM */ k: KeyFSM;
     /** mappedKeyTypes */ t: kMapKey;
-  };
+  } & ConfVersionReq
   [kBgReq.injectorRun]: {
     /** task */ t: InjectorTask;
   };
@@ -134,7 +136,7 @@ interface BgReq {
     /** mappedKeys */ m: SafeDict<string> | null;
     /** keyMap */ k: KeyFSM | null;
     /** mappedKeyTypes */ t: kMapKey;
-  };
+  } & ConfVersionReq
   [kBgReq.showHUD]: {
     /** kTip */ k?: kTip | 0
     /** text */ t?: string;
@@ -153,7 +155,7 @@ interface BgReq {
   [kBgReq.exitGrab]: Req.baseBg<kBgReq.exitGrab>;
   [kBgReq.settingsUpdate]: {
     /** delta */ d: Partial<SelectValueType<SettingsNS.FrontendSettingsSyncingItems>>;
-  };
+  } & Partial<ConfVersionReq>
   [kBgReq.url]: {
     /** url */ u?: string;
     /** use vApi.u */ U: 0 | 1 | 2 | 3
@@ -190,7 +192,7 @@ interface BgVomnibarSpecialReq {
   [kBgReq.omni_init]: {
     /** secret */ s: string
     /** payload */ l: SettingsNS.VomnibarPayload;
-  };
+  } & ConfVersionReq
   [kBgReq.omni_parsed]: {
     /** id */ i: number;
     /** search */ s: FgRes[kFgReq.parseSearchUrl];
@@ -201,7 +203,7 @@ interface BgVomnibarSpecialReq {
   };
   [kBgReq.omni_updateOptions]: {
     /** delta */ d: Partial<SelectValueType<SettingsNS.AllVomnibarItems>>;
-  };
+  } & ConfVersionReq
   [kBgReq.omni_runTeeTask]: Pick<BaseTeeTask, "t" | "s">
   [kBgReq.omni_refresh]: { /** destroy */ d: boolean }
 }
diff --git a/typings/vimium_c.d.ts b/typings/vimium_c.d.ts
index 8fb172f99..b4fa52bc9 100644
--- a/typings/vimium_c.d.ts
+++ b/typings/vimium_c.d.ts
@@ -282,7 +282,7 @@ declare const enum PortNameEnum {
 declare const enum PortType {
   initing = 0, isTop = 1, hasFocus = 2, confInherited = 4, reconnect = 8, hasCSS = 16,
   onceFreezed = 32, aboutIframe = 64, selfPages = 128, omnibar = 256, refreshInBatch = 512,
-  otherExtension = 1024, Tee = 2048,
+  otherExtension = 1024, Tee = 2048, OFFSET_SETTINGS = /** log2(4096) */ 12,
   /** for external extensions like NewTab Adapter */ CloseSelf = 999,
 }