Hi, Tom.
Quad magnets fell into the spec category for 19T when I was in Vegas. The three endorsed motors were the Chamelion 2, Reedy Quad, and the Element. Any variation on those motors were accepted as long as the endbell had locked timing and met all of the other requirements normally associated with this class. So, the DC team version of the C2 was entirely acceptable for example. Quad magnets were not endorsed for Roar stock and as such the Epic Quad was not legal.
That's about all I can say about that! Hope it helps.
Phil