What about using 100% gas, we have easy access to it here in the South..
Well, it is an apples to oranges thing. The Harley was never intended for ethanol fuel. Also, it is not a closed fuel system like a modern emissions equipped vehicle, so any moisture could be a problem. Basing what one would do from anecdotal experience with a small engine like a lawn mower, gen set, or a Harley is not really realistic. Folks in my area have been using at least E10 since the late 1970's in their vehicles. There are still plenty of vehicles running around that have been on E10 for 20 years or more. My 1974 Pontiac Catalina got E10 most of its life. The car died of body cancer at 250,000 miles, but that 400 V8 engine was still good. My 2015 2500 and 2017 Nox have been on 100 octane E85 almost exclusively for their entire time since I bought them new. Only recently have I dropped back to E30 as I have found the mpg is significantly better than E85 and not too far off from regular. So I still get premium octane performance at less than regular fuel prices.Around here 100% gas is priced good, so I use it a lot.
I've repaired friends Harleys' from the damages of ethanol to their carbs & rubber gas lines etc..