The wear tends to be greatest at highest frequencies for the obvious technical reasons. I can no longer hear the "top octave" so little consequence for me.I’m not saying that no damage happens objectively. In this type of mechanical system with a hard rock being dragged through an essentially soft surface, certainly there’s going to objectively be wear over time.
I’m pointing out that the way some people speak about the record wear can exaggerate the audible consequences. You’ve set up lots of turntables. I’ve owned my turntable for a long time and I have done plenty of comparisons myself, and I’ve got many records that I’ve listened to a great number of times, and whatever is happening objectively, subjectively the difference is so minuscule that the records tend to sound fantastic even after lots of plays, and similar to new records.
I mentioned a video in which a record was played 100 times on a decent turntable, and you can see and hear for yourself that the difference between the first player and the hundredth play was negligible.
Or at least if somebody said, it was significant serious degradation after 100 plays, I would certainly disagree with that characterization. Check it out for yourself;
OTOH the 4-channel LPs we had for a short time modulated the difference information onto an around 50kHz carrier frequency iirc, so they would perhaps be the most vulnerable to sound quality degredation I suppose.
Maybe @sergeauckland has some experience here, given he has the kit to play them?
I do remember from my days working at Garrard that the Bruel and Kjaer test records had some advice about how many times they could be used before the accuracy of the frequency response fell out of tolerance.
Anybody interested by the engineering involved in making and testing LP records and their limitations would be well advised to seek out any of their 60s and 70s technical literature.
Nothing much new has been found since then - though fashion changes what is discussed