10-12 lbs would be safe.
Thats what a DA revolver was and the same for the DA/SA semi autos. glock changed it based on nothing other than a gun for military purposes that they then marketed to the civilian market. That put the gun out of the hands of people who actually are trained to use them into hands of people that can have no training whatsoever (and the military always carries them in a holster).
Otherwise you should have a manual safety like the MP offers.