I don't think all that pain is necessary. Just dremelling/sanding is enough. Messing with the centers can lead to permanent damage of your cube. I am going with a risk-free method because I know how costly these Rubik's brands are. Also, I don't think anyone would be willing to replace rivets with screws just to change the tension.
I want you to prove me wrong by creating a video of how this is done/ and the end result.