[Damian]

First inform the captains and coaches that there will be no inbound play in the front cout on the end line. All will be on the side lines.
They won't like it but will live with it.

Then position your self out from the top of the key. You would be surprised that you will see most of the action. You a little side to side to move with the ball and occasionally you can step down on one side if needed.

During transition, move to the sideline and allow the players to pass, then position yourself out from the top of the key going the other way. On fast breaks, you can move with the ball like the C does, and stay away from the end line so you can observe all of the players.

I've had to do this several times and it works.
The good news is that you don't need to run a lot,

Hope this helps.