Hand poses should be implemented to magazine holding already.
I have seen Gadgets be added with hand poses to go along with it throughout the 3 years of being officially released.
But there's one thing that should've had the grip hand poses from the beginning but never did, despite none of the current guns ever changing aside from minimal reload animations,

and it's the magazine grip hand poses.

Sure, gameplay calls for quick hand movement that leave players focusing more on the current task, but the way the hand model cups the magazine, maybe not even touching it properly, makes the game feel unfinished despite already being a fully fledged game.