The Fast 2.0 does tune with boost. You build a target AFR map based on your map sensor. Mine for instance is a 2 bar. I just ball parked my AFR's for E85 and deliberately set them to be rich. Every time I drive the car it is more crisp. The car runs better now than it did with my dyno tuned haltech.
I think dyno tuning by an expert is still a must, because the Fast doesn't work with timing. I again went conservative with the timing map. I will hopefully get into a dyno shop next month and will report back with info and video :).