Keeping in mind a near future (our perspective) dropping of the Astral Blockade (or wahtever device the DM uses to bring Earth into things) as well the the very REAL power of pure belief in the planes (particularly the Outer Planes, might not the advent of humans familiar with SciFi movies and books kick start the development of a new transitive plane-Hyperspace?
Another take would be to have Hyperspace simply be the Ethereal/Astral/Phlogiston.
Just a late night thought inspired by looking at old game notes. I was planning a Dragonstar/Urban PS crossover Pre-K.