I still think it would be nice for the PDGA to enforce consistency upon manufacturers. When they submit a disc for approval, but then churn out discs that differ substantially from the approved shape, there is no recourse as a consumer. If they sell plastic with flaws in it that cause it to break or age differently, there is no recourse for the consumer. When they change from flat to domey, or from low PLH to high PLH, changing entirely the flight characteristics, there is no recourse for the consumer.
To enforce consistency standards by putting the onus on the player is silly. And since flattening a disc can't be detected easily, then people will do it anyways.
Note that I have never done this myself. For example, I have some domey ESP Cyclones that I've never used in a round, since they fly nothing like the earlier flat ESP Cyclones I fell in love with (I was seeking more of them). The difference in flights is night and day. I would really be interested, out of intellectual curiosity, to see if flattening these newer runs fixes them, and makes them fly like the old ones (like my 1st ace disc, which I retired). If I did so, then I wouldn't feel good about using them in PDGA-sanctioned tournaments, and I probably wouldn't. But perhaps I could write up a report and send it to Discraft, although they probably don't care (and anyways, they deny that their discs have so much variation).
Drivers: Starlite Wraith (158g), Gummy Champion Leopard (150g), 1st Run Z-Talon (150g)
Mid-Range: Star Classic Roc (146g), R-Pro Roc (157g)
Putt/Approach: Legacy Protege Clozer (158g), Glow DX Aviar (150g)