I will follow-up my above post by adding that the Walther PP/PPK system pistols do not work so well for me, when using the left index finger to press the mag release button, as I cannot reach the button while maintaining any semblance of a firing grip . This has not been a issue, for me, however, as their slides start to saw parallel grooves in the web of my hand, by the end of the first magazine, so, I have little interest in reloading my Walther PPK/s in any hurry. It is simply a fun little gun, which I reckon could be pressed into service as a back-up weapon, but is not, for now, kept loaded.
Back to the 1911, which I mentioned, previously: When shooting left-handed, releasing the mag by pushing the button with my quite flexible left index finger does not otherwise disturb my firing grip, whereas using my thumb to press that button, while shooting right-handed, requires a significant shift, in my hand, totally losing a firing grip, because my thumb cannot, otherwise, reach the mag-release button. So, my mag changes with a 1911 are actually MORE efficient, when performed lefty!
My first handgun, in late 1982 or early 1983, was a Detonics 1911. I had to use DA revolvers as duty handguns, starting in 1983/1984, in the academy, and I mostly used revolvers, for the rest of the Eighties. I used used a Colt Stainless Commander as a police duty pistol, for about a year, about March 1990 to April 1991, when it started malfunctioning. I returned to using 1911 pistols for police duty, 1997-2002, and then again 2016-2018. For personal-time defense, I was never totally without a 1911, from some time in the mid-Nineties, to the present day. Notably, as some compact Nines have become too muzzle-whippy* for my aging thumbs, hands, and wrists, the all-steel, full-sized 1911 remains an “orthopedic” weapon, easy on my old bones and joints, even shooting .45 ACP.
Back to the Glock, which I mentioned, previously: when shooting lefty, using my index finger requires a slight shift away from a full firing grip, in order to reach the mag release. When shooting righty, using my thumb requires a slight shift in my firing grip. So, with double-column-mag 9mm Glocks, there is no reason for me to want to change anything, as I have to slightly shift my firing grip, either way. I still consider my G17 and G19x pistols to be part of my defensive weaponry, but interrupted due to being unable to train adequately, in these pandemic times. Glock triggers require more-frequent practice, with live-fire, to maintain what I deem to be a reasonable skill level.
*Not just pain, but actual swelling, that persists for days. That is actual damage, being done. Pistols with full-sized grips, and some amount of heft, are now my friends.