The tricks up my sleeve... Methods I may implement for better FE.

[omgwtfbyobbq]

Umm... It should work?
Provided most of your driving is at a steady cruise, instead of boosting a smaller motor to get more power, why not go to a larger displacement motor and gear it for your driving? Imo, it'd be much more reliable, and leaning out could still be an option w/ SAFI, w/o the risks associated with running a boosted motor lean. The nice thing about the TSI is the small displacement allows for good efficiency across the board, but as long as you aren't doing a lot of city, why not build something that's just as fast if not faster, and gets ~25-30/50 mpg? Do you already have some cheap/free parts, or would this be from the ground up?

Edit-Hopefully the TSI won't follow the path of the grenade luancher on the Corrado...