I have no idea as I'm not familiar with Unity's limitations. Likely bandwidth-limited as usual. It's roughly 1 kb / sec per player, but it's cumulative as the host player needs to send the data to everyone, so if you have 11 players that's a 10 kb/sec increase from sending the new player data to existing players, then another 10 kb/sec increase from having to send other player's data to this new player.
