the way the servers are at the moment it's pretty hard - we're using the linux-only forking, and that basically means all the l4d2 servers are pretty much clones of each other, I can change variables like public/private but that's it
I don't have time to work on them at the moment, but we could change it to have no publics, and that would free up memory to be able to make the privates independant, and that'd let us configure them with sourcemod etc. (at the expense of several gigs worth of disk space per server)