Providing an update with my actual experience:
1. I arrived at Terminal 4 with my family around 2:30 PM on Sunday in July 2023. Three of us already had GE, and one (infant daughter) was conditionally approved.
2. I asked one of the staff members standing near the GE kiosks what to do with my daughter. He asked us to get in USC line and get her processed, even though me and my wife aren't USC. Within about 10 mins, an officer processed all our passports without any difficulty. I asked him about the EOA, and he directed us to the EOA room.
3. For EOA, they have a room with a dedicated officer (or two). This room was at the right-hand end of the hallway behind the immigration officers' cubicles. This is not the room at the left-hand end of the hall where they sometimes manually help people who get the 'X' slip form a kiosk (and is in front of the immigration officers' cubicles). There are prominent signs for EOA, and it would be hard to miss.
4. The sign-in process was pretty low tech. You write your name and the time of arrival in a sign-in sheet, and they call you in order.
5. There was only one officer doing interviews. It took us an hour and a half of waiting, but the actual 'interview' for the infant took about about 3 mins - what is her PASSID (the GE ID number), asking where we had arrived from, what our current address is, and holding the baby up for a picture.
6. A second officer arrived and set up shop just as we were doing our interview, which likely cut down the waiting time significantly thereafter.
7. At this location, the baggage claim carousels were freely accessible from the EOA waiting area - one could go back and forth to pick up luggage or use bathrooms while waiting.

While the long wait after a long flight was annoying, we preferred it to having to come back to JFK for a scheduled interview several months later.