While I have no experience with a real gun fight the main problem I see here is.... At every range I have ever been to muzzle pointing up out of the berm during a reload or any time will get you a very strong warning if not ejection from the range. While this may be the go to method for a gun fight it has no place in day to day practice on a club/public range.
Soud slike that's the way I do it.I slingshot, but not with two fingers. I grip the slide, pull back, and release. When reloading, your weak side hand would load the mag, then it's a short distance to moving to the top of the slide and slingshot. To me, it's a little more reliable. Pulling the slide back releases the stop first,then it's a straight shoot for the slide to slam home.