Just spoke to an Apple support member on proper care of the finish.
Using a 70 percent isopropyl alcohol wipe, 75 percent ethyl alcohol wipe, or Clorox Disinfecting Wipes, you may gently wipe the exterior surfaces of your Apple Watch
Also, I asked if you could polish the PVD coating.
No, you generally cannot polish out light scratches on a PVD coated watch as polishing will remove the coating itself, making it not recommended to try and buff out scratches on a PVD coated watch
I also confirmed that Apple Care+ does not cover scratches on the case itself.
Scratches are typically considered Cosmetic Damage (if they do not prohibit the device's function). AppleCare is most often reserved for Accidental Damages.
. . .
In years past, I have always had the silver stainless steel case. When there were scratches, I would be able to polish them out with a Cape Cod cloth. With the PVD-coated titanium finish, this seems to require more care. The natural titanium finish looks great; I absolutely love it. I understand there will be micro scratches, but what happens when you get a substantial scratch?
I would love to see if you can get away with light polishing without issue.
It has been a month; how has everyone polished Titanium finish been holding up?