Yeah setting up to force VS till hibernation of the server would work just great
but you may still want to add an off switch because and this is nothing anyone can fix till we have the SDK is once a not VS map is forced to be VS and you have 4 or more players no one can join the game (server) meaning if you start a lobby for a VS game and start the game with 8 players and change the map to Dead Air or Death Toll if anyone leaves no one can join to take their place now sticking you with bots or uneven teams for the rest of the campain. Now where I have seen this to be a problem is when all the humans on the zombie team leaves and there are only humans left on the human team and round end and now the humans players are on the zombie team and bots are now incontrol of the human team. The bots are afk so to speak and dont ever leave spawn. So having that off switch incase everyone leaves on the zombie team so you can then make the game go back to co-op and play the rest of the campain without the server getting stuck with the afk bots which the only way I have found to un-afk the bots is to team switch a real player over to the human side. Hope some of this info helps with the design.
Jay Dogg
P.S Feel free to add the radial menu to the main post