Whether to use "lavender" or "self blue" seems like a pretty minor issue, a choice of words - and the words already mean exactly the same thing. It's telling that it would be a big deal, a momentous issue to pick one or the other. In a reasonable world, the breed could have a variety called "Lavender / Self blue" without the APA blinking an eye.
I take it the current standard is unreasonably resistent to change?
In the early 1900s the Dominique club was enfuriated with the poorly written APA standard for the Dominique, and especially with an awful breed illustration that was included in it... The level of organized dissatisfaction, among breeders of what even then was a breed in declining numbers, was such that the standard was rewritten and a much better illustration by Arthur Schilling took the place of the old one.
Has anything like that happened recently?