Yes, according to Jason@Dizzy; RT Tuning (they are actually in Montgomeryville, Pa.) has already totally screwed up an S280 install on a FiST, and they flat out refuse to attempt to tune even a factory turbo FiST/EcoBoost car at all.
That owner, who is on the other FiST forums/site, was actually there on the very same day I was having them mount and balance my set of Dekagrams/Neo Gens (they did do a great job with that service, and also with simple installs like exhaust systems, etc., but charge totally insane prices for it).