I would stay away from ethanol. It will wash crud out of your tank, straight into the fuel filter, which hopefully catches it. Just not worth the cost savings for me.
The first several years I used mostly Valvtech with autogas used randomly. Treated every winter. Maybe 5 years later, I had the overheat and the boat sat un-used for nearly 9 months. That winter I put treatment into the tank. I was seriously considering getting a hazmat company to empty the tank but my mechanic constantly said not to, don't worry about it. I listened to him. The following season and after repairs, it fired right up and I ran it empty and put new gas in. No issues.
Years later, while looking for a possible gas leak [turns out it was the filler tube is leaching] I opened the tank via the sending unit and probed the tank. Clean and no sign of crud. It actually looked factory fresh. My engine, except for filters, are all original equipment. At least from 2007 when I acquired it.
I guess my point it that the fear of ethanol doesn't effect me like it did in the earlier days. As long as you run the tank down in a reasonable time frame and properly treat the tank at the end of the season, you shouldn't have any problems. I've run auto-gas, Valvtech and non-Ethanol separately or all three depending on when I need to add gas. Boat runs fine. But, I do try to make sure most or all of the auto-gas has been burned off before winter storage.
