Idea 1. Since I guess a BT server has a file where it stores map records, a command to look for maps which are "unrecorded" or changing the name's colors in the vote menu could be useful.
Idea2. If a file with all the difficulty levels for each BT map would be created, players could vote basing on the difficulty level. Also if all the players in a map keep spawning checkpoints and keep dying, that could mean they are noobs (just like me ) and none of them votes for a map in the last seconds, a map with a low level difficulty could be voted automatically.