too much chaos when you encounter a RPG face to face and the guy starts fast switching like with stubby and shotgun, it's impossible to win such a fight if you have m4 or even m6 sometimes lol
and if let's say his friends come and start blasting m4 at you, you don't know what to do, it's a dead end lol
just as molotov and grenades crouching is disallowed / disabled, same thing should be done with RPG fast switching, a good system for that would be that you need to wait 3 seconds after you switched to RPG in order to shoot, that way you can prevent abusive rocket shooting (which is too OP)