@Duke - They really give non-SCCA clubs a hard time about using the SCCA Solo classes? There are several independent clubs in our area who have all used the SCCA's classes for years!
Putting on my old-timer hat (even though I'm not THAT old), autocross at least here in the northeast was put together by independent clubs who were members of a regional council. One of the big things that the council did was standardize the classes that all member clubs ran for their events, in addition to making a points series from two of each individual club's events. When the SCCA came into the autocross business, everyone adopted their classes as standard and the councils eventually became extinct. In our area, the only thing that the Hudson Valley Council of Sports Car Clubs does now is appoint three captains to organize the New York team for the long-running Tri-State Championship, which used to be a big event between three councils but is now basically an attendance trophy for whoever is hosting it.
Long story short, outside of NASA and the marque clubs, I can only recall ever seeing one non-SCCA club that didn't run SCCA classes -- shout out :-) to Martin Sports Car Club in Orlando, Florida. I'm having a hard time believing that Topeka has taken any action against non-SCCA clubs for using their Solo classes at non-SCCA events.....
Cat herder emeritus - Poughkeepsie Sports Car Club, Inc
Solo Chair (retired) - New York Region, SCCA
AXti.me user since June 28, 2015