Well if you feel like it I need more civilian ships. Shuttles and the like. The crafts in the universe are going to vary widely, so it doesn't matter if you make non-matching shuttle styles. They can even look sportsy and stuff. Think of Sotiris's personal ships like our automobiles.I'm a bit low on inspiration on some of my own stuff so if you have any ideas for ships/stations shoot emm at me.
If that's not really your thing, then I don't mind builds that might reflect the different species building styles? Duine Sidhe have more elegant and regal building styles. (Since they're mostly all upper class individuals) Humans have a VERY specific build style that I will show some of later down the line. The Sgiathatch build more bulky/industrial when it comes to common vehicles, but imagine their military and high class vessels being serpent or dragon like.
I have yet to decide other factions at this time, but if you start making a neat unique design and want to make up a race and people to go along with it that would be awesome! Just remember, any kind of human race is off limits till I introduce them in the story. They have a special role. The Duine Sidhe are the galactic standard in this universe. Which if you have a hard time picturing still, are very Elven in appearance and culture.
If any of this interested you then I would love to see what you create and would be happy to include its designs in my chapters to come. ^~^