I don\'t know how good your math is, if you don\'t care skip to TL/DR.
The problem of jumping and turning at sector borders is caused by the way sectors work. As far as I understood every secotr has it\'s own frame of reference. These sectors now move within the frame of reference of the SolarSystem which move within the VoidSystems. The Question after transitioning from sector A to sector B is: Where did you look at?
It\'s a simple question and the crux is, there are 3 answers. The most simple one (as far as i can jduge) is the one used now. If your vector of sight in sector A is (x,y,z) it will be (x,y,z) in sector B... but seen from the frame of reference of the SolarSystem these are two completly different directions. A transformation of these vectors under consideration of the SolarSystems frame of reference could possibly stop this. But then you would still have the same effect when changing the SolarSystems.
TL/DR: The incapability of lying straight to a targeted waypoint is caused by the way sectors are designed and the way transitioning between them works.