diff --git a/battle_srv/models/room.go b/battle_srv/models/room.go
index 5df0f3c..2faba1b 100644
--- a/battle_srv/models/room.go
+++ b/battle_srv/models/room.go
@@ -188,6 +188,7 @@ type Room struct {
 	StageTileH                     int32
 	RawBattleStrToVec2DListMap     StrToVec2DListMap
 	RawBattleStrToPolygon2DListMap StrToPolygon2DListMap
+    BackendDynamicsEnabled         bool
 }
 
 const (
@@ -459,17 +460,12 @@ func (pR *Room) StartBattle() {
 			}
 
 			// Force setting all-confirmed of buffered inputFrames periodically
-			unconfirmedMask := pR.forceConfirmationIfApplicable()
-
-			dynamicsDuration := int64(0)
-			if 0 <= pR.LastAllConfirmedInputFrameId {
-				dynamicsStartedAt := utils.UnixtimeNano()
-				// Apply "all-confirmed inputFrames" to move forward "pR.CurDynamicsRenderFrameId"
-				nextDynamicsRenderFrameId := pR.ConvertToLastUsedRenderFrameId(pR.LastAllConfirmedInputFrameId, pR.InputDelayFrames)
-				Logger.Debug(fmt.Sprintf("roomId=%v, room.RenderFrameId=%v, LastAllConfirmedInputFrameId=%v, InputDelayFrames=%v, nextDynamicsRenderFrameId=%v", pR.Id, pR.RenderFrameId, pR.LastAllConfirmedInputFrameId, pR.InputDelayFrames, nextDynamicsRenderFrameId))
-				pR.applyInputFrameDownsyncDynamics(pR.CurDynamicsRenderFrameId, nextDynamicsRenderFrameId)
-				dynamicsDuration = utils.UnixtimeNano() - dynamicsStartedAt
-			}
+			unconfirmedMask := uint64(0)
+            if pR.BackendDynamicsEnabled {
+               unconfirmedMask = pR.forceConfirmationIfApplicable()
+            } else {
+               pR.markConfirmationIfApplicable()
+            }
 
 			upperToSendInputFrameId := atomic.LoadInt32(&(pR.LastAllConfirmedInputFrameId))
 			/*
@@ -481,13 +477,26 @@ func (pR *Room) StartBattle() {
 			   Hence even upon resync, it's still possible that "refRenderFrameId < frontend.chaserRenderFrameId".
 			*/
 			refRenderFrameId := pR.ConvertToGeneratingRenderFrameId(upperToSendInputFrameId) + (1 << pR.InputScaleFrames) - 1
-			// [WARNING] The following inequalities are seldom true, but just to avoid that in good network condition the frontend resyncs itself to a "too advanced frontend.renderFrameId", and then starts upsyncing "too advanced inputFrameId".
 			if refRenderFrameId > pR.RenderFrameId {
 				refRenderFrameId = pR.RenderFrameId
 			}
-			if refRenderFrameId > pR.CurDynamicsRenderFrameId {
-				refRenderFrameId = pR.CurDynamicsRenderFrameId
-			}
+
+            dynamicsDuration := int64(0)
+            if pR.BackendDynamicsEnabled {
+                if 0 <= pR.LastAllConfirmedInputFrameId {
+                    dynamicsStartedAt := utils.UnixtimeNano()
+                    // Apply "all-confirmed inputFrames" to move forward "pR.CurDynamicsRenderFrameId"
+                    nextDynamicsRenderFrameId := pR.ConvertToLastUsedRenderFrameId(pR.LastAllConfirmedInputFrameId, pR.InputDelayFrames)
+                    Logger.Debug(fmt.Sprintf("roomId=%v, room.RenderFrameId=%v, LastAllConfirmedInputFrameId=%v, InputDelayFrames=%v, nextDynamicsRenderFrameId=%v", pR.Id, pR.RenderFrameId, pR.LastAllConfirmedInputFrameId, pR.InputDelayFrames, nextDynamicsRenderFrameId))
+                    pR.applyInputFrameDownsyncDynamics(pR.CurDynamicsRenderFrameId, nextDynamicsRenderFrameId)
+                    dynamicsDuration = utils.UnixtimeNano() - dynamicsStartedAt
+                }
+
+                // [WARNING] The following inequality are seldom true, but just to avoid that in good network condition the frontend resyncs itself to a "too advanced frontend.renderFrameId", and then starts upsyncing "too advanced inputFrameId".
+                if refRenderFrameId > pR.CurDynamicsRenderFrameId {
+                    refRenderFrameId = pR.CurDynamicsRenderFrameId
+                }
+            }  
 			for playerId, player := range pR.Players {
 				if swapped := atomic.CompareAndSwapInt32(&player.BattleState, PlayerBattleStateIns.ACTIVE, PlayerBattleStateIns.ACTIVE); !swapped {
 					// [WARNING] DON'T send anything if the player is disconnected, because it could jam the channel and cause significant delay upon "battle recovery for reconnected player".
@@ -537,7 +546,7 @@ func (pR *Room) StartBattle() {
 
 					indiceInJoinIndexBooleanArr := uint32(player.JoinIndex - 1)
 					var joinMask uint64 = (1 << indiceInJoinIndexBooleanArr)
-					if MAGIC_LAST_SENT_INPUT_FRAME_ID_READDED == player.LastSentInputFrameId || 0 < (unconfirmedMask&joinMask) {
+					if pR.BackendDynamicsEnabled && (MAGIC_LAST_SENT_INPUT_FRAME_ID_READDED == player.LastSentInputFrameId || 0 < (unconfirmedMask&joinMask)) {
 						// [WARNING] Even upon "MAGIC_LAST_SENT_INPUT_FRAME_ID_READDED", it could be true that "0 == (unconfirmedMask & joinMask)"!
 						tmp := pR.RenderFrameBuffer.GetByFrameId(refRenderFrameId)
 						if nil == tmp {
@@ -801,6 +810,8 @@ func (pR *Room) OnDismissed() {
 	pR.InputFrameUpsyncDelayTolerance = 2
 	pR.MaxChasingRenderFramesPerUpdate = 10
 
+    pR.BackendDynamicsEnabled = true // [WARNING] When "false", recovery upon reconnection wouldn't work!
+
 	pR.ChooseStage()
 	pR.EffectivePlayerCount = 0
 
@@ -1068,6 +1079,43 @@ func (pR *Room) prefabInputFrameDownsync(inputFrameId int32) *pb.InputFrameDowns
 	return currInputFrameDownsync
 }
 
+func (pR *Room) markConfirmationIfApplicable() {
+	inputFrameId1 := pR.LastAllConfirmedInputFrameId+1
+    gap := int32(4) // This value is hardcoded and doesn't need be much bigger, because the backend side is supposed to never lag when "false == BackendDynamicsEnabled". 
+	inputFrameId2 := inputFrameId1+gap 
+    if inputFrameId2 > pR.InputsBuffer.EdFrameId {
+        inputFrameId2 = pR.InputsBuffer.EdFrameId
+    }
+
+    totPlayerCnt := uint32(pR.Capacity)
+    allConfirmedMask := uint64((1 << totPlayerCnt) - 1)
+    for inputFrameId := inputFrameId1; inputFrameId < inputFrameId2; inputFrameId++ {
+        tmp := pR.InputsBuffer.GetByFrameId(inputFrameId)
+        if nil == tmp {
+            panic(fmt.Sprintf("inputFrameId=%v doesn't exist for roomId=%v, this is abnormal because the server should prefab inputFrameDownsync in a most advanced pace, check the prefab logic! InputsBuffer=%v", inputFrameId, pR.Id, pR.InputsBufferString(false)))
+        }
+        inputFrameDownsync := tmp.(*pb.InputFrameDownsync)
+        for _, player := range pR.Players {
+            bufIndex := pR.toDiscreteInputsBufferIndex(inputFrameId, player.JoinIndex)
+            tmp, loaded := pR.DiscreteInputsBuffer.LoadAndDelete(bufIndex) // It's safe to "LoadAndDelete" here because the "inputFrameUpsync" of this player is already remembered by the corresponding "inputFrameDown". 
+            if !loaded {
+                continue
+            }
+            inputFrameUpsync := tmp.(*pb.InputFrameUpsync)
+            indiceInJoinIndexBooleanArr := uint32(player.JoinIndex - 1)
+            inputFrameDownsync.InputList[indiceInJoinIndexBooleanArr] = pR.EncodeUpsyncCmd(inputFrameUpsync)
+            inputFrameDownsync.ConfirmedList |= (1 << indiceInJoinIndexBooleanArr)
+        }
+
+        // Force confirmation of "inputFrame2"
+        if allConfirmedMask == inputFrameDownsync.ConfirmedList {     
+            pR.onInputFrameDownsyncAllConfirmed(inputFrameDownsync, -1)
+        } else {
+            break
+        }
+    }
+}
+
 func (pR *Room) forceConfirmationIfApplicable() uint64 {
 	// Force confirmation of non-all-confirmed inputFrame EXACTLY ONE AT A TIME, returns the non-confirmed mask of players, e.g. in a 4-player-battle returning 1001 means that players with JoinIndex=1 and JoinIndex=4 are non-confirmed for inputFrameId2
 	renderFrameId1 := (pR.RenderFrameId - pR.NstDelayFrames) // the renderFrameId which should've been rendered on frontend