A 1911 is designed to be carried cocked and locked. A 4566 is not a 1911. Thats one of the reasons I love the 4566.
I would never suggest to anyone that it is wise, or safe practice, to lower the hammer on a l911, with a loaded chamber, using your thumb and forefinger. IMO that is not safe gun handling and begging for a ND. IF you do that, you are not operating the gun as it was designed.
The 4566 was designed to use a decocker to safely lower the hammer on a loaded chamber. A 4566 is not a revolver. And I cannot think of a single DA/SA designed pistol that does not have a decocker incorporated to safely lower the hammer on a loaded chamber.
So put me on the list of those who SERIOUSLY thinks this is not only a bad idea, but right up near the top of the list of bad ideas. Good luck to those who operate handguns outside of their designed parameters or try to turn perfectly designed DA/SA pistols into 1911's.
Regards 18DAI