No, no difference at all, either side, from light pressure right to left, or left to right, on the ambi Slide Stop Lever.
But, I will say, you are definitely on to something. When my gun was experiencing the drag, you could visibly see the right side of the Slide Stop Lever move "out" slightly as the trigger approached release. As in, it would physically move ever so slightly sideways.
So yes, I think the theory that the right side of the Slide Stop Lever has a lot to do with my issue is probably correct. "At this time" however I don't see the same movement, noting the trigger group parts (Trigger with trigger bar, Slide stop lever, Trigger mechanism housing with ejector, and connector) were all cleaned with Hoppe's and a Q tip/patch then reassembled today. So it's actually not too bad, but for sure, does not feel like my G26.5's nice rolling break (200 rounds), at all.
I'd look at options for Slide stop levers for the Gen 5 which did not have the right side of the bar, or Dremel it off, but being a lefty I use that side all the time to lock the slide back.
But who knows. At least I can (now) fairly easily swap in parts to see whether the trigger action is restored to similar to what I really liked when I bought the gun originally (smooth rolling break.)
Yes, I realize a Glock is not a 1911, but I'd kinda like it to work as well as I can get it to.
Question for you guys: Does the Firing Pin Safety have much to do with trigger smoothness in the Gen 5s? The Gen 5 of course has a redesigned pin profile, almost like a wedge shape. If I clean that up with a buffing wheel and some Flitz, will that help much? A a few years ago, when I replaced my S&W M&P 1.0 striker block with an Apex Ultimate Striker Block; that had a huge positive impact on the smoothess of the press; hence the question.