All good points. This thread has got me to thinking... I am now considering a light 45 (like a Kimber Ultra) and practice practice practice for muscle memory with its thumb safety. Then if I have to draw the Glock under pressure, it won't cost any measurable time if I try to flip a nonexistent thumb switch while preparing to fire the weapon.
I think. (?)
I think this is a better scenario than the first (working between 3 different modus operandi).
Stay safe,