Good point. 

I'd like to add another 'predisposition', as my ever requested issue is, that all those GC3 races origin from paradise earth-like planets. 

I'm currently building a mod based upon C.J.Cherryh's Alliance-Union universe and to catch all of them would need to base them on methane or other heavy extreme planets instead. Can't imagine how to make them living on earth planets without dramatical changes. Only availible option is to build them as synthetics right now or to open them level 1 extreme planets, but that's not really fitting. 

Needed would be: 

- modding in other then the current availible starting planets...say level 2 or 3 extreme planets as starting

- cutting down usability of usual planets...even to zero to allow total different faction designs

I really do guess the devs have cutted out extreme-world start for later DLC.     

Don't think this is the best solution as I rate this aspect to be of basic interest. 

Quoting Blaze of Glory,

reply 4

I would like to see modifiers for earth-like, jungle, mountainous, etc. and each faction has a preferred type. A bonus on their type and penalties for other types. A planet of the undead......

A Reaver planet like from the Firefly series... now that is would be interesting.