Germany had this discussion some years ago when they also moved from E5 to E10. Consumers demanded E5 back, and the last time I was in Germany, tanks offered both E5 and E10 among others.
Same in Denmark. We have an Octane 100 Which is E5. The rest is E10
From when I did some research on it, E10 can be problematic for engines that are not prepared for it. It can cause rust in tanks, damage to hoses and seals among other. If the engine is made for E10, there should be absolutely no reason not to run on E10 except for lower effect/higher consumption.... on some engine. On my car engine, I tend to feel that the turbo like the 5 % extra ethanol.
If you store your MC during winter and the tank is metal, you should either empty it or fill it to the max