To elaborate on my question: I have a rather big collection of Gurps Traveller books at home, and since Alien Races 3 my favorite spot in the Traveller universe is the Crucis Margin sector - where the Third Imperium, the Hive Federation und the Two-Thousand Worlds are looming shadows in the background, where a lot of self-devised planets and minor races might be placed and where you might encounter strange folk like the Ithklur or Lithkind or, dare I mention them, the ubiquitous Droyne.
By the way: In my opinion no Traveller campaign is worth its salt without some Droyne-encounters now and then.
So, in how far does the T20 core book already support such exotic ambitions?