"One problem with the part wearing down is that the gun may stop staying open when the magazine is empty."
Sorry but, that particular problem is NOT caused by using the Slide Stop to release the slide. Nope!
Some small parts of some 1911 format pistols are of lesser quality than the identical part in another "make" of pistol.
Concerning the Slide Stop;
If the slide stop on a carry pistol ever shows any sign of metal deformation then it should be switched out for a higher quality properly hardened part.
A properly machined and hardened Slide Stop should not deform.
The part should be properly hardened to a degree that it will not wear or deform.
The Slide Stop
Notch on the slide will usually show a tiny bit of normal deformation in that you may at some point notice a small raised edge.
That does NOT happen from using the Slide Stop as a Slide Release.
THAT happens gradually as the slide is stopped by the Slide Stop (during the normal functioning of the handgun) and does not affect the operation or functioning of the pistol.
As modern slides are now harder and tougher than the older slides it is not so common of an event anymore but, it means nothing regardless.
There should be NO problems with using the slide stop as a slide release if the shooter wants to use it as a slide release.
Sling shotting your slide as part of your training regimen (and to develop desired muscle memory) is fine and dandy.
Do it for the correct reason though.
Do not do it because you think you are "SAVING" your pistol from any sort of unnatural or undue wear or "STRESS" to either the Slide Stop or the slide by releasing the slide using the stop.
That is just not so.
If your Slide Stop is wearing or think it is being "Stressed" then you need to do some shopping at Brownell's for a higher quality hardened and tougher part.
Some people will always want to baby a pistol & nurture it and Kiss its A$$ because they think it is beautiful and they paid a lot of money for it.
That is their personality & That is fine with me but, what is NOT fine is that they invent things that "should and should not" be done...for the "good of the pistol" that have no real basis in historical
or mechanical fact.
Then the myth feeds on itself and finally it becomes so common that it's accepted as truth.
If using your Slide Stop as a slide release damages or deforms parts on your pistol then you either have a sub-standard pistol or a pistol with sub-modern-standard parts.