You can still use the differential receivers but they do not add independent ports. They have to be assigned to physical ports on the f16 and they share the amount of pixels available to that port.
You assign it to the port. When you sign in to the falcon you pick which 4 ports the f16 will share with the 4 ports on the diff. It has to be ports 1-4,5-8,9-12,13-16 and so on. So when you look at the diff. it would have port 1a, 2a, 3a, 4a if you took the first four. If you string another diff. off the first one it would have ports 1b-4b. There is a good YouTube video by Canispater Christmas (Jeff Lacey) that does a good job of explaining it.