Update - I got my bio-metrics apt, OF COURSE it falls right in the middle of my trip.

I did a walk-in and the lady said "They changed the system, there's only one tech today. You'll have to mark the checkbox to reschedule and send it". I told her I could wait and that I would be out of town, even showed her proof of my trip and she hesitated and said "no, just check the box and mail it so they reschedule you because the system changed"

So no more walk-ins, apparently. sigh.