Unfortunately, the Stepper Online drives we are using don't have that type of functionality. You would need Torque Control on the Stepper Drives like the torque loop on an industrial Servo Drives i.e. you reduce the Holding Torque via Torque Control analogue input and then you could move the joint with just enough torque to allow for re-positioning but not collapse. Then, your position loop would also have to be disabled to prevent position or following errors.