I'm going to see if I can get some pics of the 2 Epics my buddy carries. Trust me, there's no way "normal wear and tear" could ever make discs look like this.
The Epic is specifically designed to be tuned and was PDGA Approved (now grandfathered) with the Tech Standards guys (before my time) knowing that was the nature of the product. So it would be legal under the rules to tune the disc per manufacturer instructions. If tuning was against the rules, a statement would have been made by Tech Standards excluding that if it were not going to be allowed.