Jazz - the outputs aren't in use, though - I agree - strange setting, but the M3/M4 relay outputs = OUTPUT1, but that's ignored with the wiring from the VFD 'X1' input (factory default : Run fwd) through the VFD switch to ground - confirmed by OP with the VFD switch switching the Run indicator on/off.

I'm more curious of : configuring the VFD to use the pot (F002 = 3, as factory, rather than original 1 - analogue input) seems to cause the VFD to crap out with an error - at the first time that it's able to present a none-zero demand. At this stage I'm wondering if the VFD has been configured for the spindle, or if there's a fault in the spindle or the wiring.