Your point is fair, but I can even take a "certified" motor and put a 6.5 turn stator in it. So by that reasoning, it doesn't matter whether it's certified. It just has to say 17.5 on the can to fool others into thinking that's what you're running (until they see you clearing quads).

There are 17.5 motors out there which are not ROAR legal yet but are otherwise a copy of a ROAR legal design (case in point - Turnigy Trackstar motors are basically a Reedy Sonic copy). Then there are 17.5 motors which used to be ROAR legal, like the D3.5. I think there's a difference between the two, and in the latter case, ROAR basically screwed up and created a gray area. Lots of people bought the D3.5 and it would be hard for a track owner to force a customer to spend another $80 on a non-banned motor. So far at least, there doesn't appear to be much or any controversy at RCHR about what 17.5 motor people ar running, and it seems to be going ok for the time being. The bigger issue, I think, is boost, and that has a far greater effect than any difference between a D3.5 and a legal 17.5 motor. Boost is not allowed in our 17.5 classes, and if we suspect somebody, then we tech them.