Hmm. If the lever on the side of the 1911 was never intended as a slide release, I wonder why they bothered to checker it and make it stick out so much? If one hand is disabled, having a prominent slide release does not seem like a bad idea.
Sometimes drinking the Glock Kool-Aid and applying it to other guns makes little sense. If your gun has a flat slide stop and your finger is apt to slide off, do not use it as a slide release.
If it has a prominent slide release that sticks well out from the gun and is specifically roughened for good purchase and happens to be within reach of the support hand as the magazine is inserted, this is no more a fine motor skill than hitting the mag release button and is actually much less so. If such a gun is your regular carry piece speedier reloads are obtained with no loss of reliability.
If all your guns are Glock inspired or your mix the two types better learn the slower method.