And this is to do what? Prevent the slide stop from being pushed out by a very tight holster?
As I said on another post, the slide stop in a 1911 type pistol is supposed to be made so it cannot move to the left except at the takedown notch. If it can, that shows that the gun maker had no idea what he was doing or how the system is supposed to work.
Yes, in rare cases, an extra tight holster can cause problems. When the gun is inserted into the holster, the holster pushes back the slide and if tight in the area above the trigger guard can also push in on the slide stop and disable the gun.
But hundreds of thousands of Model 1911's were carried in holsters for what must be a total of centuries without that happening and it would be a very bad holster that would cause it. Sounds a bit like a solution to a non-problem but they are, after all, your guns.