I evaluated all three guns.
The Springfield 1911-A1 45 Stainless has the longest depression needed, maybe more than half way needed.
The Springfield 1911-A1 9mm and Remington R1 have about the same and maybe 40% needed to release.
Also, there seems to be a higher tension on the 45 A1.
And, as mentioned, when I put my thumb on the safety, it creates a little pocket, but not so much that it turns on the safety.
BTW I never have this problem with my XDm.
I am going to take them out to the range and give them another run and see if I can figure out if this is grip/training or one of the guns has more of an issue for my hands.
Thanks for all the great posts.
Cody