I can confirm that running e-85 with the OFT tune, absolutely adds 15-20 hp. I love running the car on e-85, it feels much more perky and alive. If there were more stations that sold e-85 around me, I would only use e-85 on the car. Its that much better.I'm really not familiar with this info around e-85 adding power. I'd have to look into that. It doesn't sound realistic to me... but I'm no expect.
Adding 50 WHP to an NA engine this small would take a massive built. Forget just intake, headers, exhaust, some mapping, etc. You'd need to open it up for sure.