As known from other Games, there should be a reserved slots feature.
People with the priv "reservedslot" should be able to connect, even if the playerlimit is reached.
This could be solved by a mod which kicks the latest joining players when maxplayers-2 is reached.
Engine support would be better.
So the admin (and his friends) can always connect.
Alternative:
Kick last 2 Players or 2 Random Players when a privileged player connects.
