So how deos the 1911 fire without its trigger being pulled. I've got a Kimber CDP II 5" right here.
Safety off, I'm shakin it, dropping it, playing with the trigger takeup, spinning it on my finger like a cowboy.....still nothing.
I wouldn't worry about the thumb break it really isn't needed. As long as you have a good holster that covers the trigger your set. I prefere the MTAC holster for 1911's and Glocks.
Seriously, the 1911 is a pretty safe gun. Been carrying mine for years, sometimes I do bump the safety off. I wouldn't worry 'bout it.
I had a day where I was working in "bumpy" conditions, so I decided to carry empty chamber for a while. I decided that would be a good day to experiment with the hammer cocked and the safety off.
Since it was an empty chamber, if the hammer accidentaly fell because the safety was off, then nothing would happen.
At the end of the week, the hammer was still cocked after all that time without the safety on.
Even without the safety off and no thumbbreak and rough handleing for a week, hammer never fell.
So proper carry, cocked and locked= perfectly safe, even without the thumbreak.