Not good to take chances on this.
Vehicles older than 1994 may be especially vulnerable. Ethanol will loosen up junk in the tank and lines that gets into the fuel filter, but ‘94 or newer vehicles (in good condition) should adjust to E10 blends after a tank or two.
I have a ‘91 GMC pickup with 200,000 miles that does fine on E10, but it’s been digesting it for years. The big V8 loses only a couple mpgs, so sometimes the price spread is worth it and sometimes it’s not.
And no ethanol blends in small engines unless the instructions say ethanol blends are OK.
you just nailed the problem am having.