Have high-power turbocharged piston engines been run on ethanol in service? I’m not aware of any. GA piston fleet has the common property where 20% of the fleet burns 70+% of the fuel as they are working airplanes. (Think CapeAir and similar in passenger service.) Those highly stressed turbocharged engines have lower detonation margins, currently requiring tetraethyl lead additive to meet worst case detonation margins.