I would like an "auto orbit correction" feature that could lock an orbit's shape and periodicity to a specific set value.
This would be useful for orbits that cross another planet's orbit without entering their SOI. Since small nudges during docking and turning could affect the orbit shape, gradually adding to a non-synchronized orbit (causing your craft to enter the SOI), which ruins the orbit.
This feature could, for example, only exist if you have RCS on board, and the RCS can become spent after a set amount of years.