Here it is: an enhanced server-side max-viewing distance.
I think this would reduce the amount of active blocks in the server's memory,
thus enabling a steady flow out to all of the connected clients.
It would be tapered down according to how many are connected.
example: 2 people on, max view 160
6 people on: max view 120
10 people on: max view 100
The owner of the server can determine the best numbers for smooth game-play.