I concur ethanol is hard on vintage carburetor engine parts. I've see this year, over year, in my 1980s Yamaha Scooter hobby, as well as most muscle cars before the 1990s. Storage, too, seems to be poor with ethanol fuels. I have to rebuild scooter carbs every 3-5 years, and there is often the same powdery residue left behind. Despite using decent fuel filters.
Sadly, I live in California, where people and legislation is uppity. You don't really get much choice, out here. If they did, I would avoid ethanol fuels in older vehicles.