Sector based movement wouldn't be a good idea in my opinion. Didn't SM used to have this and it made moving from sector to give annoying reorientation? I can't tell you how many times I used to be so close to a planet, only to get reoriented AWAY from the planet.
What about planets being free entities of their own and having a pathfinding AI that simulates orbital movement? That way, sectors stay static, planets revolve around stars, and navigation is only tougher for the planets themselves, which is pretty cool in a way. Having sectors rotate is just messy, because the whole point of sectors or cardinals is that they're static and can be used for navigation. With planets moving as AI, you could control the speed of orbit (even based off of planet mass) by referencing the planet size in a variable and doing calculations, or randomly, and even having varying orbit shapes like how Pluto for instance actually travels on an elliptical orbit.
How this would actually perform in game though is what I'd be worried about. Planets seemed to get less and less laggy every update, so I'm sure that there might be wiggle room on the performance level. There would also need to be a way to keep titans from literally knocking them out of their "orbits", which I would have no clue abut what would need to be done.
Your orientation will never need to change. Inside the same orbit, it's exactly the same. Going between orbits will result in some offset in position being necessary, but no orientation changes are needed, because ithe sectors are all square internally. Imagine a brick wall, and each brick is a sector. You can't just copy your position when you go up to the next row, but you don't need to change orientation.
As for "sectors are static" well, I'm just using "sector" to describe the enclosed reference systems that Starmade already has. The fact that these reference planes no longer have static relations to each other is no big deal. Currently, planet sectors rotate. Having translation differences is less of a hassle.
As for planets moving inside sectors, that would be a nightmare. My system has the advantage that planets are moving at zero velocity. No needing to accelerate to catch up with them. If you've every tried docking on a moving ship, that's hard. Now imagine every single base is like that. No way. Also, no need to worry about a titan knocking a planet out of orbit, since the planets are static entities, and don't move.
Also, having a "sector" that moves with the planet or orbiting station means using jump drives to get there is super easy. You don't need to calculate where the planet is, you already know where it is, because its sector stays the same.
I think it would be easier to get rid of the sector system entire.y if this was implemented. Only after a certain point can fixing it become more of a hassle than redesigning it, and this is that point. one solar system would be in its own sector, with all planets in orbit. The FTL warps would be taken to the gate liked to it. Simple. Not some coordinate, the gate.
The problem is then a sever has to load EVERYTHING in a system, and the systems next to it. Good luck with that. The sectors not only act as reference frames, they also allow the server to decide what to load or not, in a very simple way. Is it in a loaded sector? If so, load it.
