Ethanol Fuel Mixtures in a 2009 E93

[dgb75]

I'm curious as to what the ramifications are of running an M3 off of a richer ethanol mixture than the E10 that's typically found at the pump. I've heard BMW has been hedging that higher-ethanol fuels would become more prevalent, so supposedly the seals should be Ok, but I read about that while discussing a 335i, not an M3. So does this hold with the M3, and if so can it take a 30% Ethanol mixture on a regular basis?