This suggestion, while taking realism into account, isn’t the entire point. It isn’t really fun to fight a CI with an RPG due to the fact it’s basically an instant win for the CI in question.
If guns need to be balanced, then they should be balanced but relying on one weapon that instantly kills people who can’t react to it (As it’s impossible due to the close quarters nature of it) isn’t fun.
I think the RPG outdoors is fine, but indoors makes raids completely unfair. If guns aren’t balanced? Suggest the balance.