Those special case systems (IMHO) are solving the wrong problem. Uber airport queues should be exactly like taxi queues: the passenger at the front of the queue takes the taxi at the front of the queue and you're done. No more which car is yours, let me find a spot, block other cars while we load, etc, etc.
At Newark, for instance, Uber drivers regularly take 10-30 minutes to show up after accepting your ride, and even then, they'll often call you and ask you meet on a different floor, one specifically meant for private cars, not car hire services, because the traffic on the floor they're supposed to pick you up on is so very busy.
It's far better to just do front of queue matching and let the passengers scan a QR code that establishes that driver as their driver for the trip. No more brinksmanship of ordering an Uber when you deplane and hoping you are ready with your luggage around the time your driver arrives.