The mag release has a tiny finger on it that's reaching out to the back of the follower. I would argue that by pressing the mag release with a magazine inserted raises the possibility of the finger snapping off because you're fighting the pressure of the spring with the force of the pressing. The magazine is pressing the catch upwards but once it locks the bolt back, the spring tension is relieved until you start pressing into the mag release. It's fighting the rearward pressure along with the downward pressure now.
I would argue that if you're worried about the bcg causing damage, I would argue that you'd probably break the bolt catch long before you arrive to that kind of problem.
I would just release the magazine, pull the charging handle back a little to get the bolt catch out of the way, then slowly ride the assembly home. But as others said, it probably won't harm the rifle by slamming it home though but it's best to do what you feel comfortable.