Hi Everyone, thanks for the replies. I can't say at this point that I have had any particular malfunction that ties directly to my thumb hitting the slide due to pressure on the safety. I've simply noticed a few times that I am either millimeters away or actually touching it after shooting. That's at a range. Even when I dry fire I try to replicate my live fire grip and I am always very tight in to the edge of the slide. In a self-defense situation everything is amplified and I could see applying sufficient pressure to impede the slide. I am tempted to avoid the slide altogether but it is too bad because it feels natural.