Those aren’t modifications. But call it whatever your mind of average intelligent wants.
Once you redesigned those parts you and assembled them in a new lower receiver you have a weapon designed for civilian use. That weapon is not capable of automatic fire. It was never marketed for battle field use. STILL waiting for you tell me why.
So we are back to your hatred of those who are attracted to that semi auto sports rifle designed for and built for civilian use. Based on appearance.