wraitii has a patch for supporting random maps on serializationtestmode at #3615
saving a copy of the map terrain to every savegame sounds like a waste of disk space
It's not clear whether serializing the terrain on the hosting computer, then transfering it across the network is faster than computing it from the matchsettings.
Bandwidth and the performance load on the host should be minimized, so that observer-join-lag is minimized.
