Is it possible to place the required shell command into a downloaded copy of the config file and then upload that file to m0n0wall?
I had the same idea.. Using <shellcmd>, however since the gif0 interface apparently doesn't exist until a while after boot, the cmd executes too early..
At least that's what I'm guessing.. Attempted it, and it didn't work :S
But I figure the setting should be part of the tunnel setup on the WAN page.. Would make the most sense, no?