I believe that falls under the "object container streaming" system slated for 3.3 (end of Q3), which a new engine system for efficiently nesting containers. Situations like a room in a ship in a hangar in a space station in a planet's orbit in a star system, such that the parts you need can load in and out seamlessly.

There's also related work with getting things like ship spawning off the main thread and improving the networking so that it only sends you data that's relevant to areas you're in.

Hopefully this stuff doesn't get pushed further down the schedule because it should make a big difference to performance.

You can see their development roadmap online: https://robertsspaceindustries.com/roadmap/board/1-Star-Citi...