The problem with the idea of a training server with 24/7 watch is, there's no way you could get people to make sure the server is supervised, unless you'd pay them to do so...
Sure, people volunteer at first, because they're excited at being a moderator, but then they lose interest, and it feels like a chore. I myself can only stand a couple of hours tops of ESF.
I run a game server (I tend to change the game every few weeks) myself, but I feel that, the only way one could be sure that there's a moderator (or even a person playing) is when I myself am on it. People don't like bots (I myself browse a server's player list before joining), and the more bots on a server, the less chance people want to join. Likewise, the less people on a server, the less people want to join. On some games it's because the bots are capable of accomplishing feats and tasks humans can't, but in ESF it's just because they suck so much, and do nothing but ramble on unless the admin has the decency to disable the voices.
AND THAT is why a training server is hard to manage, and why a supervised server is so difficult to accomplish.