Actually, some airports *are* set up for ITI/TWOV, at least to a certain extent. For example, DFW Terminal D has a massive (and deserted) international transit lounge located near the passport control checkpoint. I've never seen anyone inside. I suppose it could be used if CBP ever decided to allow ITI/TWOV again. (or maybe it is used infrequently to accommodate inadmissible visitors who are waiting to return to their country of origin)