Maybe the default Orbiter package could contain one additional star, like Proxima Centauri, with a few planets.
Not a bad idea, but why bother with it when there're plenty of star systems on the OH already?
In addition, the community can continue the Orbiter Galaxy effort.
Its developer is involved in two ongoing projects right now and not going to switch back to OG for a while.
Then, it would be a blast to see the community create additional ships specifically for interstellar flights (which would require 'generational' ships).
I did this using IMS and OrbiterGalaxy together. It's working the way it is, if little clumsy.