I also think that this is mainly a balance issue. as seen in the video above you can very well do it, and even if it was used that way in 1 out of 1000 cases, it was still possible and, even if extreme rarely, used that way.
I think the balance issue could be easily handled with on paper.
Give it another weaponslot like the bar has for hip and tripoad.
Add a 2 seconds build up time to simulate the soldier going in and out the right stance for hipfire when switching the weapon slots.
This will make him immobile and therefore exposed to aimed fire.
Round it up with an adequat level of inaccuracy.More or less accurate burts burst up to 70 yards like mentioned in that video sounds reasonable.
What also helps versus abuse is limiting it to a 3/4-round burst in which shots 2-4 are considerably less accurate than the first one.
That and the fact that you wont have an ironsight will make sure there wont be any mid to lang range abuse. Expect for "tryhards" who would put a small dot onto the middle of their screen. Which you also could counter with a random deviation for the first shot that is alsways slightly around the point you really are aiming at.
Anyway after such a long pause ("North Africa times") i couldnt care less about these things. I'm so happy i can enjoy the best mod ever created (after dota
) with or without hipfire from mg42s!