One way to implement a hardware lock is simply to put a toggle switch in the power line (plus, not ground). Literally power it off when it is not being used. When powered up, it will "re-sync" itself.
Neither "disappearing" or "reappearing" will affect the actual Duet and/or print job progress.
DC42 and the folks at Duet/Escher can't really "recommend" or "support" this, because, in theory, power cycling COULD cause some kind of problem someday... and power cycling just flatly makes design engineers uncomfortable. 🙂
However, as an end user, I can say I've unplugged and re-plugged PanelDue devices from Duets that were printing, many times. I've even upgraded PanelDue firmware (unplug, carry to computer, upgrade, carry back to printer, plug in) during the middle of a multi day print.
Your decision...