I mean, we can add some sort of a loading zone(like in KSP) where the object orbits and the voxels are rendered but it acts like a point(with the characteristics of the object) until there is an object a certain distance from the primary object.. Yes, the game is supposed to be Single-Shard, but I don't think this would be such a huge problem. I'm fine with Patched Conics orbits, and have automated calculations doing it all for you.
Also, I wanted to bring another point to the game: will the engines run on handwavium or have actual rocket-sciency stuff to it(Specific Impulse, radiation(if nuclear), heat generation, that sort of thing.