I carry a compact 1911 everyday that I can for the past few months that I've had my permit. It has an ambi safety. Never once unholstered at the end of the day to find the safety off and I routinely check throughout the day cuz I'm paranoid. It rides in a milt sparks vm2 holster. The holster has a detent in it for the left side thumb safety. I've tried to flip the safety off with it in the holster just to see if it was possible(unloaded of course). And without feeling like I was close to breaking the safety off it was extremely difficult. With my gun/holster combo I'm not too worried about it.