I was following a pacer the other day (Cyril Citrine) and was hoping that we would catch a slower pacer so that I could back off my effort for the end of my workout.
Of course I could have just teleported (sorry Zwift word) to the Eddy Emerald group, but if I knew we were only minutes behind Eddy and would likely catch that group, I could just continue with the faster group until that happened.
The same in the other way, I usually start riding alone and if caught by a pacer group I join them but if I get caught by a slower group first, knowing the faster group was coming up behind would be good to know.
Maybe have a pane below the list of near by riders showing the gap to the other pacers on the same route.