The monitor is in all of the maps, but it also has the monitor beam in the weapons, so I am not sure if it is ready for forge in the beta. It might be possible to get forge using a new forceloading xex specifically for forge.
as for forge in the beta i think its unlikely. whenever you try to play as the monitor it freezes, there is items on the maps with forge as a preset and what looks like peices to make a racetrack on boneyard however they cant be loaded. the monitor beam cant be loaded either. in scnr there isnt anything from what i cant find any forge pallettes so you could spawn objects.