I think the main advantage of an E-85 tune is the opportunity to run a lot more advance, since ping is mitigated by the cooling and anti-ping capability of the ethanol. So unless you're running a lot of timing, or aggressive timing, in a N/A application, I wouldn't see much issue. You'll know if the engine pings when hot on acceleration.
Unfortunately, I've found pump gas to very quite a bit in the ethanol concentration, or at least what the car senses as ethanol concentration. We run E-10 here, and I've seen measured (from the car) 5% to 12% concentrations. Not sure I'd tune to the ragged edge of that.