There is a glaring issue with 3.x that isn’t spoken much of at the moment that can be easily fixed going forward: Switching from a standing position to a crouched one or prone will still allow the player to fire or do an action while switching between them. This obviously to those who are nuanced in PvP currently in 3.x know that doing this will almost always win in a 1v1 fight.
To very easily fix this this issue for later versions of 3.x and onward into 4.x, a very simple thing to make it so that when doing said action and switching stances, it cancels out and makes players unable to preform actions while transitioning. Also, making the time to switch between stances slower than they are right now will also greatly discourage players from switching stances in the middle of combat unless protected. Also, switching stances should have better animations to better represent these changes if our one true god decides to go through with these