Just found another one by chance. It can be used to make the server have unlimited time. xD.
Ok, go play against some bots. Type in /restart, and while the end scoreboard is displayed, type /pause, and then /unpause.
Hmm... did that just cancel the restart?
You can do this at the end of a round to make the server have unlimited time. xD.
Just thought I'd share it about. It's good to know that if you mistakenly type /restart, there's a way to stop it. Lol.