Wrong method of resetting after the last round lockback. SPD armorer instructed me that using the holdback lever causes wear. just rack the slide again.
It really shouldn't. There are guys out there with 10's of 1,000's of fired rounds through their Glocks (like me) who've never had a problem. The usual argument is whether or not to go, 'hand-over-top' (HOT) in order to release the slide, or to just use your thumb to release the slide stop. (Which Glock, GmbH is now calling a, 'slide release' - Ahh, the power of gaming!) 'Reset' is, also, a term that applies mostly to a Glock's trigger mechanism. Which is, as far as I know, the only thing that ever actually, 'resets' on a Glock. The slide is most often either, 'racked' or simply, 'returned-to-battery'.
I agree that it shouldn't, but I respect the armorer (It's her fault I went Glock.) You are right, reset is more the trigger function (and one of the things that won me over to the Glock, same armorer.) I will likely never be in a situation where I have to do a combat reload. I don't even shoot competitively. So I don't think it will matter in the long run.
Its cheap and easy enough to replace if it does. My G21 hasn't after 15k rounds and counting. It worth noting that Glock sells an extended one, so they must acknowledge that its being used to drop the slide.
For it's intended purpose...to lock the slide back. To load....in a stress situation....one should train with the movement that requires the least amount of fine motor skills....cause that will generally go out the window. Regardless if they offer one or not....practice the way you will have to use it.