Can't compensate for chemical composition. Rubber and aluminum degrade and corrode quickly with ethanol so most flex fuel systems use different materials. E85 in these trucks will lead to issues down the road like clogged injectors and damaged fuel pumps.I’m sure the tune compensated for the fuel mix, but just to confirm what others are saying here is a photo.
I'm with @Alabama Mud Machine on the real benefits... a few hp here and there are nice but at least on the Tacoma side, the improved throttle response and improved shift logic was a massive improvement in the real driveability. The HP gains you only enjoy when you romp it but throttle response is gold 100% of the time.