I learned to shoot when magnum revolvers were the standard. That meant firm shooting grip with even firmer secondary grip "locking down" the shooting hand's fingertips and thumb.
To this day I still shoot thumb down with the off-hand thumb locking it down. I've never had a problem with any semiautomatic - 1911 especially, engaging the safety during firing...the gun simply doesn't kick that hard if one is holding is properly.
Especially with the 1911, if one places the shooting thumb down, with the support thumb on top, shooting grips "relaxed," yet support grips firm, the 1911 can be fired extremely fast with amazing accuracy.
The "thumbs forward" grip....I can see ZERO rationale behind it other than some expert somewhere who shoots attenuated loads through weakly sprung guns. The standard 1911 thumb safety does NOT lend itself to a thumb laying all on top of it, but of course the myriad of aftermarket, giganto-size thumb safeties DO, but such a hold does NOT provide a truly solid hold for a pistol IN A GUNFIGHT! You wouldn't grip a hammer with your thumb alongside the handle (unless you wanted it to come loose) and you don't grip a pistol you may have to use as a bludgeon with your thumb out of position to RETAIN the gun in your hand against being knocked aside, or having to resort to using it to beat someone across the face and head as fast as possible. Sorry if that seems a bit indelicate, but it's the reality of real-life combat with another person trying to kill you after you pumped half-a-dozen rounds into him!
The human hand is designed to CLOSE AROUND an object in order to exert maximum gripping force, and this is the "natural tendency" of the hand. Deliberately training to grip in such a way as to create significant distance between the thumb and index finger is deliberately setting the hand up with a WEAK grip which means easy, and early loss of control of whatever is held in the hand.
Besides I have found zero "improvement" to be had from laying the shooting thumb atop the support thumb other than a goofy, "loose hold" that does nothing positive to improve accuracy.
Granted there is a "YHUGE" difference in how an experienced pistolero can grasp any variety of handguns versus the novice simply because the pistolero already knows the handling and recoil characteristics and has confidence of control. Unfortunately too many novices are being taught range techniques that do not apply to the real world, not I might add, do they follow the natural "fight or flight" response which should be the cornerstone of ALL martial training, including and especially firearms training.
