Lifted directly from west system in a tech article:
"With the increasing use of alcohol and other high-tech additives, we are unsure how epoxy will resist them in the future. We do know that many types of alcohol vigorously attack epoxy; we can only conclude that gasoline with a higher percentage of alcohol may break down an epoxy coating over a long period of time."
And from my time working in the lab... Back when I ran our lab we used a couple dozen different epoxies for various testing measures. Clean up consisted of one of two practices... Heat the plates to 500 degrees and the stuff crumbles right off as you scrape, or soak in regular old E10 for a few hours and the majority of them were like play-doh. There were a couple that were pretty resilient and a few of those were used in industry for tank manufacture that I am aware of.
There certainly are plenty of epoxy-fiberglass tanks in service in industry that have nice long life cycles. It certainly is done just fine. I have a dozen just at my plant....
Not trying to stir the pot or anything, sorry if that's how it came off.