A flex fuel enabled tune is not the same thing as an E85 tune.  A flex fuel tune, once it’s dialed in, will automatically adjust timing, fueling, and a couple other parameters based on different blends of ethanol automatically.  It does this by “inferring” ethanol content based on the feedback provided by the O2 sensor readings.  The process can be somewhat inaccurate with some latency however and thus, you should not expect to have an aggressive tune as your flex fuel tune.  This type of tune should simply be used for convenience!  For those of you who want this extra convenience, a separate hotter track tune will be provided to switch to for track days when you know you have good E85 in the tank.