Is there a standing issue with Dark Fortress generation for custom entities? One of the civs I'm putting together tries to spawn Dark Fortresses in deserts, but, in such a state, the game crashes instantly the moment it's done placing civs. Swapping them out for cities, causes it to work flawlessly. I can only assume its the fortresses.
Unrelatedly, is it possible to make custom sites entirely?
Yes, my personal theory based on my play experience, reading of observations made about the tags introduced with 47. and testing is that demons experimenting interactions render them unable to be playable as well with any other race designated this way, with no real way to install a alternative demonic leaders who are compatible because [UNIQUE_DEMON] is not considered egible in absence of a empty underworld or other circumstances like demon experiments being turned off in advanced world settings.
Generated demons nor dark towers can be seperated from one another, leading to the game crashing or the tower never generating in the first place if either condition is absent.
And no, but there are two unintentionally working tokens with dubious playability PLAYER_FORTRESS (creates sole hillocks) and MONUMENT (only occupies world-structures like castles & tombs, known to crash a lot), Layer linked civilizations are also playable with quirks related to location and lack of map presence, but if you ever want to interact with them, i suppose you would need to dip into DFhack to summon caravans (overground? underground i dont know)
Its on paper a theoretical way to add more trading partners without overloading the world with too many entities.