Yes, you should be fine driving like that for a short period of time until you get a tune. Technically, that advice is correct: there is no need for a tune with a TBE. The reasons why almost everybody gets tuned at that point are (1) to eliminate check engine lights, (2) to maximize power, and (3) to help ensure the car runs safely for a long period of time.
And, yeah, I'd also try to stay out of boost as much as possible - just to be safe.
07 WRX (Albins 5MT + Blouch 20G)
Jorge Carrillo Tuned (365 whp/340 wtq)