I tried this out while briefly experimenting with a pistol grip stock, and was not impressed with it in any way. It’s intended to block the mag release from moving however it just made it spongy and I’m not sure it would stay in place. I suppose it did prevent the mag from dropping but I doubt it would have held up to a forcible attempt. Lesson learned - for the money one could just get a spare mag release and grind the paddle end off.
Anyways - rather than toss it I figured I’d see if anyone here could use it.