I had my renewal interview at JFK (T4) a few weeks ago. When you entered the office, you signed in via a book at the entrance. There were one or two people who did not have appointments, but got to speak with an agent. One of these was sent away; I only got a little piece of his issue, he said CPB in T1 "instructed" him to go to GE (T4), he got into a slight argument when he was turned away.