Great you figured the game breaking bug! Waiting for the new release!
Indeed, it's cool to have many galaxies and stars.
So here's an idea. People don't remember or miss them. You can look into "data mocking". You can have some default data and reuse that. Just do the display, don't even generate anything initially. Just start in random data points. Or maybe use a seed. When the player looks, generate that single object, just-in-time.
Only save it if it is bookmarked or has buildings or is in the last 10 places visited by the player, limit history to 10 places. Save only the important things. Or the seed.
Also unused stuff should be put "on rails" like in Kerbal Space Program.
Hope it helps!
Nice attitude, keep it up! I'll be rooting for you!