There is a very long history on this that I don't have time to recount here. But the short version is that tried to convince the PDGA Board to require all variants of models (basically variations of plastic from what was originally submitted, tested, approved, and certified for use in PDGA events) of approved models to be tested about two decades ago. About a decade ago, the Board finally supported me and so we required variants to be submitted and tested. But some of the manufacturers pitched a fit, claiming that that was too government, that it was too onerous for them to have to submit so many discs for testing. The Board was pressured to reverse their decision and they did so. So now we are left with the current situation, where manufacturers can but are not required to submit disc variants for testing, and even when they do submit them, the PDGA does not require a fee for doing so.