We run our pa18-95 on mogas never had any probs ( touches wood) it's PFA and a C90 Continental. Always generous with the carb heat. They're supposed to be more iffy at higher altitudes, but who goes up there in a Cub?
Sorry it doesn't help your situation but just letting you know that mogas in some engines is not a problem.
CC
PS Can Dakotas run on mogas? ;-)