Almost sounds like the product Plexus which was designed for the aircraft industry to seal and protect plastic windshields. It adds a micro-thin layer of wax that actually fills in the tiny scratches. I've been using it for years on motorcycle windscreens, fiberglass panels and helmets. Also for window tint films, plastic headlight/tailight covers, and clear instrument panels. Spray it on and wipe it down with a microfiber towel and you'll find a super smooth surface with the very fine scratches now invisible. A product like standard Polywatch or Novus is more abrasive and will do a better job at actually polishing a plastic surface, but for day to day use the product above or a Plexus product might be useful.
I find it interesting that I can find lots of ads for this product online, but no independent reviews yet. I think I’ll wait for those before I even think about using it. And I probably wouldn’t anyway — I expect my watches to get dings and scratches. I would post a pic of the back lugs of my watches here, but don’t want to give some members a heart attack!