Dynamically , and Computing the 50 closest players, to each given player, with so many players is no easy task.
Then when you have some players randomly leaving or joining, it becomes even more complex.
I was in a large MP session a few days ago (Forderlearntofly stream) and my plane, that was showing up earlier with my MS ID, had changed to UNKNOWN.
Disconnected from server & re-joined, and my correct name came back up.
My plane itself was always visible … and I obviously have no idea what went wrong or where, but I am sure if it was Easy, it may not have so many difficulties – (he says, stating the obvious),
Just had never seen the “UNKNOWN” Tag before !!!