Tesla UI in fact warns you if you set the charge level to more than 90% for more than 1 day in a row. 90% is the value they suggest.

I have so far "babied" my battery and max charge at 70% outside of road trips. So far, my degradation is right on track as average, which I assume is people doing the 90% charge trick - so trying to outsmart the battery hasn't worked for me yet.