What else is left to work as expansion material? The only thing I can think of is specific religion/cult.
Perhaps it's better to ask which SciFi trope they actually have addressed?
I can't play the Tampies from Timothy Zahn's Warhorse. Biological ships aren't available let alone tamed starfaring beasts.
I can't play the Quaddies from Free Falling by Lois McMaster Bujold who had four arms and burrow into asteroids with tiny space stations, unable to even work in normal or lunar gravity. Habitats can't even the touch asteroid belts they call home.
I can't play the people of Kensho with their "psionic" symbiosis with an extra dimensional entity, the Mu'shin and their ability to teleport from planet to planet at the end of the series. Dennis Schmidt's series is not available.
I can't send out a generation ship or a solar sail ship. You see references to these technologies but . . . you can't play with them at all. So all the science fiction related to them is simply off the table, not really addressed.
How about all the other FTL methods that were in the original game and got scrapped? We can't choose to play a game with them even one that limits the game to JUST one of them.
We sort of have robotic based life but it's not "tapped" you can't have totally space faring machines with robotic shipyards and no ability to settle planets, where the ships ARE the civilization. Droids and cyborgs just don't do it. The closest we come are the mining drones you sometimes have to fight.
And what about silicon based life? Why are they on terrestrial worlds? Earth started out as a C02 and methane planet like Venus. Without the great oxgenation and with silicon based or alternative biology why are we limited to worlds that are variations on the Earth? That is a huge Science Fiction trope we haven't touched. Ditto with gas giant eco-systems. I'd love to play species like we find in Allan Dean Foster's "Sentenced to Prism". But we can't!
Speaking of which what about genetically engineering humans to live on places like Mars or Titan? Why doesn't the Biological ascendancy add in the ability to live on more planet types though genetic engineering? That would make it compete a LOT better with the robots. lol
And
We have barely scratched the surface of . . . well most of my favorite science fiction novels. I get the feeling this game is produced by people who mostly focus on Warhammer, Star Wars and Star Trek . . . Not Asimov and hard science fiction. We certainly don't get the gravitic technology from James Hogan's Geneseis machine or the Gentle Giants of Ganymede series . . .
Nor do we see anything like the PARTNERSHIP between man and a computer network found in his "Two Faces of Tomorrow". I guess that book could become a rogue servitor situation, but when the story ends they are looking towards the stars together without the decadence. We don't get that.
It's like the guys developing the game never read Allan, Foster, Hogan, Asimov . . . and to add insult to injury they keep naming the patches after the great names of Science fiction. I'd love to see depth in anything. Give me an expansion (not a pack) that really goes into depth with biology and biological ships, warhorses, genetic engineering to settle all worlds . . . and really give us diversity there.
Then go and do the same with psionics, settling space and being nomadic, mineral based/silicon life forms, faster than life travel . . . There is so much they could do. They haven't scratched the surface yet.