I agree with Chris and Tom,
Jimmy I'm sure you are wrong, when we started running brushless you had to run ones that were on the list, I remember Derek Brady explaining the point at every regional at drivers briefing (who wasn't listening
).
At scruitineering for any regional we should by rights have the homologation cells and motors list and check all cars. We don't as a rule but that's on the basis people aren't deliberatly running non legal kit.
Remember rules help control the fun!