Trajectory changing while rotating ship
Craft with small parts (<30kg mass but no so small that their mass is centered on the ship) act as if they accelerate when rotating.
In the attached savefile, start the small probe rotating:
+ its intercept with Duna changes by distances larger than the orbital radius of Ike,
+ the small triangle above the altimeter is orange, indicating the craft is under acceleration so no quick-saving.
Related to #26898
Workaround from that issue works here as well (beware possible side effects regarding dropping parts during EVA constructions, speculated at that thread) editing 'hPhysics.cfg' to change the line with 'partRBMassMin' to
partRBMassMin = 0.005
Some mods have lighter parts that can be independent rigid bodies, specifically the GP-004 grip pad from Breaking Ground used in some examples posted above. So for games including these parts, a lower minimum
partRBMassMin = 0.002