often, you have to wait pretty long (5min) until someone joins your Duel Server.

It would be nice to see the spawnpoints in Warmup like in old CPMA.
Or just do a green quake sign/Point for it
Or spawning a not moving Keel/Bot who needs to get found and "fragged".
So he respawns somewhere else.

Maybe create a console command for it, to switch from off to on.

Second thing I would like to suggest,
how about a working timer for warmup? now its only 0:00 when you pickup anything.

Would be nice to have a timer when server is empty, so you could practice timing when youre alone and waiting.