In my case it wont happen, because my machine is a plasma CNC.
UPS is wired only to the CNC controller, not the plasma cutter itself. Plasma cutters have high current needs, so a UPS for it would be too expensive. After the power outage, the plasma ARC OK signal stops, and the CNC stop the cut. So I can start again from that point after the power back, any time because the DRO was saved after MACH 3 closes and save the XML.
With other kind of machines as a mill, yes, it would be a bigger problem.
Thank you,