Servo position control with speed and torque feedforward

Hi,

Yaskawa servopacks have inputs for speed and torque feedforward (analog 0-10V) when controlled in position mode, which look useful for fine-tuning the servos with aggressive moves.

Are the joint-vel-cmd and joint-acc-cmd the appropriate HAL pins to feed these inputs? Do they need to be scaled by a fixed value or go through an extra PID loop?

They are feedforward to a PID loop inside the drive, so another PID is unnecessary.
Both will need a fixed scaling, assuming that the inputs are analogue voltage too, rather than engineering units. Though whether this scaling is done in the drive or in LinuxCNC might be a choice you need to make.
I think that I would scale in LinuxCNC for easier online tuning.