It also says something about writing to them for express permission, and keeping the letter authorizing a change with you at all race events...
With that in mind, I'd suspect that if an idea is truly a good idea, and doesn't give an unfair advantage, or make racing more costly, they may just approve. It's worth a try if you're really serious. Write and ask. What have you got to loose? So far it's a no, but maybe it could be a yes...
Good luck,
Mike