diff --git a/frontend/assets/scripts/Map.js b/frontend/assets/scripts/Map.js
index f8faba0..0ff0609 100644
--- a/frontend/assets/scripts/Map.js
+++ b/frontend/assets/scripts/Map.js
@@ -748,8 +748,9 @@ cc.Class({
       self.battleState = ALL_BATTLE_STATES.IN_BATTLE;
     }
 
+    // [WARNING] "cc.Node.removeChild" would trigger massive update of rendering nodes, thus a performance impact at the beginning of battle, avoid it by just moving the widget to infinitely far away!  
     if (self.countdownToBeginGameNode && self.countdownToBeginGameNode.parent) {
-      self.countdownToBeginGameNode.parent.removeChild(self.countdownToBeginGameNode);
+      self.countdownToBeginGameNode.setPosition(cc.v2(Number.MAX_VALUE, Number.MAX_VALUE));
     }
 
     if (null != self.musicEffectManagerScriptIns) {
@@ -1233,8 +1234,10 @@ othersForcedDownsyncRenderFrame=${JSON.stringify(othersForcedDownsyncRenderFrame
 
   hideFindingPlayersGUI(rdf) {
     const self = this;
-    if (null == self.findingPlayerNode.parent) return;
-    self.findingPlayerNode.parent.removeChild(self.findingPlayerNode);
+    // [WARNING] "cc.Node.removeChild" would trigger massive update of rendering nodes, thus a performance impact at the beginning of battle, avoid it by just moving the widget to infinitely far away!  
+    if (self.findingPlayerNode && self.findingPlayerNode.parent) {
+      self.findingPlayerNode.setPosition(cc.v2(Number.MAX_VALUE, Number.MAX_VALUE));
+    }
   },
 
   onBattleReadyToStart(rdf /* pb.RoomDownsyncFrame */ ) {
diff --git a/jsexport/battle/battle.go b/jsexport/battle/battle.go
index 7609025..d072aab 100644
--- a/jsexport/battle/battle.go
+++ b/jsexport/battle/battle.go
@@ -22,7 +22,12 @@ const (
 	GRAVITY_X = int32(0)
 	GRAVITY_Y = -int32(float64(0.5) * WORLD_TO_VIRTUAL_GRID_RATIO) // makes all "playerCollider.Y" a multiple of 0.5 in all cases
 
-	INPUT_DELAY_FRAMES = int32(6)  // in the count of render frames
+	INPUT_DELAY_FRAMES = int32(6) // in the count of render frames
+
+	/*
+	   [WARNING]
+	   Experimentally having an input rate > 15 (e.g., 60 >> 2) doesn't improve multiplayer smoothness, in fact higher input rate often results in higher packet loss (both TCP and UDP) thus higher wrong prediction rate!
+	*/
 	INPUT_SCALE_FRAMES = uint32(2) // inputDelayedAndScaledFrameId = ((originalFrameId - InputDelayFrames) >> InputScaleFrames)
 
 	SP_ATK_LOOKUP_FRAMES = int32(5)