I tried changing Iconia 2, 3, &4 from  dead worlds to barren & got  errors like so "C:\Users\James\Documents\My Games\GalCiv3\Mods\Fixed Synthetics\Game\PlanetDefs.xml(156,39): error: value 'BarrenWorld' not in enumeration", upon looking in the PlanetTraitDefs.xsd the xsd's it references only have Habitable, Dead, GasGiant & Uninhabitable seeming to prevent us from starting anyone with a functional extreme world in their system.  Given yor starting with adaptable, iconia 2-4 should be BarrenWorld, FrozenWorld, just Habitable or something .  class0 habitable/dead gives a useful for synthetics planet with a PopulationCapYor as any other planet, no usable tiles, and a population affected by econ starbases.The ability to store a large population & dplit the draw between thr class 0 & iconia allows you to send out colony ships without draining iconia so badly that it can't effectively build the next assembly