Mentioning the slide release is just a relative data point about my grip size to the frame size. Most will immediately understand the issue when you frame it that way.
I do train all methods though, but the P80 has red dot. Sometimes easier at the range to use the slide release when I don't want to smudge the red dot with my hand. But I've made sure I can rack it every which way with the red dot, including dry racking off a table to ensure it will maintain zero in adverse conditions.
I'm left handed and as such have avoided using the slide release/lock to drop the slide. It works sometimes on some guns, but isn't something I can count on.
I've been experimenting with a red dot on my G19. I like it. One of the things I like best is how great it is to drop the slide. I don't notice smudges and frankly with a big handle like that hanging off the slide would not suggest that you avoid it. Smudges be damned.
My 5'1"wife (with proportionally small hands) shoots a Gen4 G34. She has no trouble overhanding the slide or dropping mags. If you can do this reasonably well, you will NOT gain anything by going to a 43. Especially since a 43 is nowhere near as shootable as the 19. Shot to shot recovery is much slower with the 43 than it is with the 19.
You may gain a slight benefit in ergonomics, but you will most definitely have a gun that is much more difficult to shoot quickly with reasonable accuracy.
Now, if you are interested in teh 43 because its easier to conceal, that makes sense. You are trading shootability for conceal-ability. But swapping shootability for a very slight improvement in manipulation ergonomics is definitely not worth it.