Great idea, it's indeed a horrible job to have to set up the zones.
Still only applies to new maps though unfortunately.
I also maintain a Surf server, no timers as KSF, but there are jails. Players shouldn't be able to kill people inside jail, when they are not inside jail. There are also areas players shouldn't be able to enter, so there should be a kill trigger there.
Came across Dev Zones:
https://forums.alliedmods.net/showthread.php?t=220979
Should work, and has a few nice third party addons (such as a solution to my jail problem).