Couple of suggestions if they are possible.
1:Add a cvar that sets the prep time of the 1st round, so instead of the default 30 seconds it could be set to 45 seconds (or higher), just to give people who do not have the map, a small extra bit of time to download and join the game.
As it can get a bit boring sitting around for 5 to 12 minutes just because you were 5 seconds to late in joining.
....You mean ttt_preptime_seconds?
Because it already exists.