While I don't have specific experience with KPIT, I did something recently at a very busy Class B airport (KIAD - Dulles, VA). I requested a low-approach only, terminating in a climbing left turnout to the west. It took a bit of patience (and delay vectors) as they worked me in. I'd say I had a 50/50 chance of getting it... depends on the controller and the kind of day they're having.
At the time, I was a VFR only pilot, but I filed an IFR flight plan with "VFR/025" in the altitude block (standard practice for a VFR DC-SFRA flight plan) - this technique forwards my flight plan to ATC and clues them in that I'm a VFR flight. I've also found it to be helpful in non DC-SFRA flights at towered fields. It produces a strip and saves time on the frequency having to relay AC type, etc.
Last year I was "cleared for the option" at KIAD. But this was at the height of the pandemic hysteria, so the airspace was nearly empty and the controllers were bored.