I think it would be fun to do a new location project like the old Meltwater project - a small location where we describe places, people and what is going on in fairly big detail. This makes for a useful "drop in" location or a home base.
My suggestion in this case is a asteroid belt habitat. They can be very variable, make great stopover points or hiding places.
Some initial ideas: the place was colonized fairly early as a mining outpost (so it better be a M-type asteroid). 22 Kalliope seems to fit the bill - it also has a moon, Linus. This seems to be a great place to get a lot of metal easily, so it would be a natural place to set up industry for further colonization somewhere around BF 50.
Mining companies that might have been involved or still be present include Zbrny Group (maybe they run a mysterious mining operation at Linus nobody can touch?), Triple Peaks Prospecting (they did the original 44 Nysa mining), MMX-Espaço, Lukos (now defunct), Fa Jing (of course), Carajás Mineração e Metalurgia (defunct).
However, M-type asteroids are relatively poor in water and other volatiles, so the place needed to import this from the outer system or comets, making it relatively dependent on trade. As the outer system industrialized and nanotech got better demand for metal also dropped, likely driving the habitat into a depression (Detroit in space?) This might have happened around BF 20, priming the habitat to split off into independence - or sell out to someone.
Then comes the Fall - refugee influx, the new owners might go bust or mutate into something else. Chaos and upheaval, potentially tensions between people aligned with the emerging PC, the Extropians and the Autonomists.
Overall, I get the feeling of a fairly industrial place. Old, somewhat decaying infrastructure. A stopover point for some shipping. Perhaps a bit like a British northern town, trying to reinvent itself since the big mine closed, dealing with an immigrant population, hardcore oldtimers clinging to the old traditions, and a few people with ideas to renew the place.
What do you say? Can we create an interesting environment out of this?
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"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -Benjamin Franklin