E0 in all my small engines. Seafoam splash occasionally in them providing fuel system is relatively clean.
Got a older SeaDoo and Seafoamed it but system was too dirty, green algae in it, and the Seafoam loosened it up and the green gunk plugged the tiny filters in the inlets of the Mikuni carbs on it. PITA to pull the carbs on it to remove and clean them. That's why I caution on using it in some dirty fuel systems. That stuff really works.
Always use a fuel stabilizer in my gas cans, I use a marine one and buy it buy the big jug as I've got a lot of small engines to maintain and go by the ounce of prevention rule as when I need it to start and run I don't want any issues like chain saws that may sit for a long time but when that tree falls down it has to be go time.