PID Controllers and the Attitude Controller in MechJeb are problematic things.

Many old issues with MJ and the PID Controllers can be solved by using the "HybridController" under the "Attittude Controller" menu, which should reduce oscillations.

Given that we know the available torque and forces on the vessel and the MoI, we should be able to solve that problem analytically using Calculus of Variations, which is what I believe what spacecraft actually use, and not PID controllers, which may be a better way forwards for NextGen MechJeb attitude control.

Known minor issues:

• The KosController does not obey the AttitudeController's AxisControl booleans

Major issues:

• Gimbal response rate is a thing