I can tell you from experience I have not had any issues with my small engines in years after buying carbs every year it seems prior to buying the no ethanol gas.
Problem is that if the same hose/pump is used for both ethanol and ethanol free, then there can be come ethanol gas that gets in your tank prior to ethanol free coming out. If they share a hose, put the first gallon or two in your car, then pump it into your gas tank for the mower.
QTs here have different hoses for each.
