Most TSA agents know very little about the APEC program. The Memphis office has very limited office hours and completely ignorant about the requirements. I was going through Las Vegas (walk in) and the agent (actually wearing an oak leaf... never seen a TSA agent with anything but stripes or at most a silver bar) didn’t even hesitate collecting my signature and giving final approval of the application. I already had a Global Entry card. The preliminary approval online happened almost immediately. But then again, I am HKG based so maybe that makes a difference.