Eff why eye, a quicker way of restarting a map in Synergy is to use an in-game console command to switch level, eg:

map d2_prison_08

In my experience, this method also seems more reliable than restarting the server when it comes to spawning key mission NPCs.

Also, there is a secret command in Synergy which eliminates some of the problems and makes the mod more stable. Just enter this command when you start up a server:

mp_friendlyfire 1

Toodles!