Don't need it. Air Force SOF units didn't have them on their carbines until they got M4's which is fairly recent.
If and when you have a malfunction, IF you hit that forward assist, you just [bleep] yourself.
The only purpose it can possibly serve, is to ensure the bolt is completely in battery after a press check. And even this is moot ,'cause if you load the gun properly and check for crossover, you don't need to presscheck it.
