To save money when practicing, I ordered an M&P 2.0 Compact 9 with thumb safety. It has the same manual of arms as my Colt Combat Commander .45.
It does differ in that the M&P allows the operator to move the slide while the thumb safety is engaged.
Shooting the M&P, I stopped taking the gun off safety when needing to manipulate the slide. When I went back to the .45, that caused problems. I'd try to rack the slide, and the safety would prevent that.
Now, even though it's not needed, I always take off the M&P thumb safety when I need to manipulate the slide to keep things consistent, then put the safety back on.