Most polymer laminating systems will eventually breakdown in presence of ethanol and that includes both epoxies and vinyl esters. The resistance to breakdown is in the degree of crosslinking of the resin; higher linking, higher resistance. Most epoxies get the higher linking by heat curing. A 350F curing epoxy will have high linking and will withstand solvents like ethanol. A room temp epoxy has lower cross linking density and will be suseptible to eventual breakdown.
Polysulphide sealants are formulated to resist breakdown and make good fuel/ethanol seals.
The Rhino 9700 novalac is a coating with great chemical breakdown resistance, however it is brittle and can develop cracks over time, especially if the tank sees any flexing. I have used the 9700 as a protective barrier for the RT cure epoxy but it eventually cracks and that allows ethanol fuel to come in contact with laminating epoxy. I did find a flexible polysulphide from Spruce ( $38/qt kit) that is brushable and now use it whenever I want to seal tank joints that might flex. Has worked well for 2+ yrs on Pulsar integral glass tanks.