The ethenol doesnt run in boats is absolute malarky, at least according the owners manual of the 2021 Yamaha 115 v-tech. The first thing I did after the repower was check the manual for fuel recomendations. The manual states very clearly that the engine is deigned, engineered, built and tuned to run 86 octane (one lower than the cheapest regular gas) with up to 10% ETHENOL I am going to beleive the folks that buillt it and, more importantly, guarentee and warranty the engine over anybody else.
The ethenol myth started because old fuel lines had a liner that would seperate from the outer hose that did degrade in ethenol then those lines would many times suck closed inside the line and starve the engine for fuel. Some took advantage and used the situation to take advantage of folks and blame it on ethenol fuel, which is technically true but easily corrected with new fuel lines.