I wouldn't worry about the m2 since its a sturdy light, but with cheaper lights the holstering and unholstering process can be the most damaging.
The problem with "light bearing" Kydex holsters is that they retention mostly on the light itself. The trigger guard has to be covered over so that the light can pass through the holster. The only spot you can really get retention on the actual gun, is the chamber.
I was making a few hk45ct holsters for the TLR-7a and learned a lot about this.