I personally like forward assist. I'm glad I have it on my AP4 (which I use for deer hunting). It allows me to quietly load a round into the chamber. Otherwise, I have to let the action slam forward, which is loud.
Someone once showed me a trick with a homebuilt A1. Slab-sided, no FA or shell deflector. I had brought up this very subject.
He eased a round into the chamber and of course the bolt stopped just short of locking up.
Then he stuck his thumb in the ejection port, and using the notch in the carrier (for the ejection port latch) he pushed the bolt into lockup.
I have tried it and it works!
Of course I have a FA and don't
NEED to do it this way, but I like knowing that I could if I had to.