Well I had to think about this a bit and check some things, but it basically comes down to this. Whatever works for you. It's your gun, you bought it, do whatever you want. If you don't care about the wear, go ahead and use the slide release/stop. If you want your gun to last forever, don't. Some folks buy a mustang and drive 20 miles an hour on the highway, others run it balls to the wall every chance they get. Who's to say which way is "right"?
That being said, I'm going to tell you why you SHOULD NOT use it and you should be pulling the slide back to release it and I actually read this somewhere else. Releasing the slide with the release/stop is a fine motor skill. Releasing by pulling the slide is a gross motor skill. With thick gloves on or if you hands are covered in mud or blood, you're more likely going to be able to rack the slide than use the release/stop. The other is during a fast mag change, you may get nothing but air and then you have a big problem. The last reason for using the slide itself is that it's the same as your malfunction drills, so it takes one last thing out of the picture. Simple is better.
Yes, I'm guilty of using my slide release/stop, yes, I've done it on an empty chamber (I can see you cringing), No, it's not a habit nor do I train like that. yes, I try not to.