There is STEAM mod https://steamcommunity.com/sharedfiles/filedetails/?id=369840407 but it have a problems - player can conquest only 1 UB of other civ`s and this UB is buggy - their buildingclass not working. For example lf you conquer arabia and build bazaar, you can't build next building 'bank'. So, i try other way - create a special buldingclass for all UB and separate them, for example: New Bazaar only give gold from oasis and extra-luxury and give to city free-building market. But this is not ideal. Maybe people from civfanatics have idea, how solve this (Conquest UB) in other ways? P.S. Sorry for my bad english language.