It would be cool if StarMade has not fixed sectors, but points of interests which spawn sectors and are connected.
A ship which jumps, would create it's own sector, just for itself.
Whenever you are too far from a planet or a high-mass ship defining a sector, you would make your own.
Other ships can merge your sector. A bigger ship can consume your sector into it's own.
But whenever a ship leaves, there must be a decision who belongs to the new and who to the old sector. That can be done with fleet commands (all your ships join) or tractor grapples (you follow an enemy ship). Or just by being closer to the leaver than to the sector anchor when they are like 10km away.
Every ship - per default - aligns itself to the nearest universe, galaxy, sun or planet until it reaches a "pocket-dimension box" which contains the planet and rotates in this absolute space. It doesn't really matter how far. Not even for weapon ranges.
EDIT: Simpler explanation: You can lock sectors close by as if they are touching each other, but they would fade like from one snapshot into another. You can aim at specific points, fly toward them.
The projectiles would then enter the target sector so that they aim at your specified point, but that doesn't garanteue that they are instant-hit, because their entry is delayed by the seconds of distance in light years of both sectors.
When your ship sector collides with a planet sector, it drops out of warp and merges into that planet sector, probably the orbit sector around the planet sector within that orbit sector.
BTW: You can also let the current sectors be, but let ships behave like they had such sectors for anchoring and during warp they are in a sector between sectors.
Between X14 and X15 you go into XWARPID1493958 and it changes while ship is in warp-flight where you come out or which sector-transition leads you into this warp-sector.