Can I home to the Z channel? Yes, One way to establish intitial position for some rotary applications is to home to a Z channel (index pulse), rather than a home switch.
Be sure that the AUX-P (and if necessary, V I/O) is only pulled up to 5V. Wire the Z+ to HOM and the Z- to ground.
Z channel pulses tend to be rather narrow so using a slow homing velocity near the index region will be necessary.