Zhukov,
The obstacle preventing us from just making an official Demiurg list is the varied collaboration between Forge World and Specialist Games. However, Andy Chambers made the stats for the Stronghold so I don't think the Demiurg is any FW employees baby.
We lost the master for Demiurg escorts, but we do have the Demiurg looking escort from the Rogue Trader escort blister.
Another problem is the shear boring nature of having a single class of cruiser, with no escorts and only one light BB.
The best solution IMO is to have a comprehensive RT list that can be warped into a Demiurg list, Kroot List or Pirate list.
Cheers,
RayB HA