I'm not sure if they changed the design lately. But I had one and removed the fill neck and billet cap for the hanger assembly and install them in a larger cell with a sump. I use the hanger for the stock level sensor and I use a big Aeromotive external pump under the car now.
I have no true research or science to share but you and I may be long dead and buried before the alcohol eats that billet aluminum cap. And the plastic will be here when the earth is swallowed by the swelling sun.
However, I use 93 gasoline in mine.