Yes, either like out multi-Z machines docs:machines:triplez [OpenBuilds Documentation] and docs:machines:doublez [OpenBuilds Documentation] (wiring motors in parallel, ensure motors have good electrical specs like our motors does) Or if you don't need the usual dual-Ys you can reflash firmware with "ganged Z" option ticked to use the spare driver for Z instead
Good news! I would gladly try the Blackbox! When the LR3 homes the Z both motors trigger a microswitch at each side (guess you are familiar with or have heard of the LR?), will this work as intended? Specs attached… Thanks!
We may need some help from the grblHAL develops (autosquare, because most of machines has dual Y motors not dual Z) uses the Z input for Y2 (z never homes with Y). But in yours both are Z, so we may need to ask @terjeio's help change the BlackBox plugin so if Autosquare is for Z, it uses Y's input as the 2nd Z switch, so just make sure to log a request https://github.com/grblHAL/ESP32/issues in time before you need it
You can have dual Y (with autosquare) but not also dual Z (with autosquare). You can have dual Y (without autosquare) with dual Z (possibly with autosquare but then we'd need grblHAL developer help) You can have dual Y with autosquare (already built in) and dual Z without autosquare (Autosquare = using two switches for homing to "square" up the axis)