Hmmm thread necro!!
I think it is a real shame that you abandoned this world. I'm a big fan of Spelljammer and I don't think I've seen a world quite like this in SJ canon. Obviously it is only a seed, and you need to solve things like the water-cycle of a world where the seas would vanish and rivers would dump water into a black hole. But I think it has a ton of promise and you could tie your solutions into your backstory.
Hollow World is a world on the inside of a hollow planet, while this is a normal planet that essentially has a black hole instead of a core and void instead of sea. That is a totally different starting point, so I really wouldn't see it as a rip off. (It might look more like a rip off if your societies were all based on the Gazetters, from Classic D&D, but you don't seem to have done much yet, so I would have thought that you could backtrack and go in another direction without too much trouble.)
BTW: If you ever do decide to restart this, and don't want to fill this thread up with RPG stats and stuff like how your world disaster fits in with SJ's First Unhuman War and other events, maybe you could split the work between Cartographer's Guild (where you can concentrate on the maps) and another forum (where you can talk in great detail about the geeky crunchy stuff).
David "Big Mac" Shepheard
New to cartography and seeking advice - eventual goal to make a large number of maps for the many worlds of the Spelljammer Campaign Setting
Hmmm thread necro!!
Cheers, Julien
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