The other fantasy classic dwarves (also hobbits?) exist as the "squats" a modified human race that were dropped out of production by Games Workshop and sidelined by the lore.
Something about Dwarves couldn't translate into Sci-Fi, possibly because two of the central aspects of dwarves ,industrialism and being underground, are eclipsed by the scale of outer space conflicts.
But is possible to have Dwarves in Space being Dwarvish?
I don't think you could add them now to Warhammer 40 K , as any new faction some amount of Starcraft and/or Lovecraft to be taking seriously.
However here's my attempt at a Space-Dwarves that would fit in the earlier 40K warhammer.
Their origins indicate they were human , descended from humans that left with slower than light travel.
From there they increasingly compromised their humanity for the advancement of technology and the requirements of space travel.
Eventually being able to survive and traverse blackholes and making use of the super dense materials and energys they mine there.
Their form is now inseparable from their pressure suits, the being inside a oily like mass of bio-slime and crude nano bots.
The requirements for their extreme existence have turned their society into one of absolute routine and conformity, spending millennium maintaining and improving their ships, gathering materials, and drifting through space.
Their ships are like brutalist sculpture or soviet reactor.
|(Center for the Performing Arts, Albany)|
Divorcing themselves from imagination and frivolous individuality is one of their solutions to the threat of Chaos.
Their goals now is render the universe safe from chaos, which involves converting anything that chaos could invest into the equivalent of concrete dams, like the apocalyptic madness of "paperclip making AI".
While not having access to the warp , they claim to have outlasted the universe and seen it loop over , allowing them to have already traveled to where they need to be.
Their ships are undetectable and vast fleets can be calmly traveling at sub light speeds, having traveled millions of years to arrive just as another fleet arrives out of the warp.
Their technology and weapons would involve moduleness , gravity, magnetism , and weird time effects, weird materials, blackholes, super bullets and railguns.
Aesthetically drawing from any human like technology which looks threatening or overwhelming to human scale, so brutalism, big massive lines, hostile cubic detail.
Additionally add signs of pitting and crust from the vast ages of their craft.
The central ideas and required horribleness (warhammer) would be the fear of technology and overly applied rationality to transform things into unrecognizable alienity, as well as fears of deep time, and the unblinking gaze of those hidden behind protective suits
(Arnaldo Pomodoro sculptures)