That's correct, the D parameters in M563 commands are not driver numbers, they are extruder numbers. Your M584 command defines two extruders on drivers 7 and 8, and those extruders will be numbered 0 and 1 for the purposes of the M563 command.
The PanelDue instructions tell you that the maximum resistance per conductor should not exceed 0.1 ohm. You should check whether 24awg wire is thick enough to meet this requirement.
@dc42 One of the things I am worried about is setting mix ratio between channels driven on the board and channels off. I see in another thread that this can be an issue. I need to synchronize the concrete extruder axis (160watt - NEMA 34) with a smaller color dispensing stepper (~20 watts - NEMA 23) Do you anticipate an issue configuring tools with mix ratios with both onboard and external drivers?(Perhaps question for separate thread)
