[deleted] As flighty_sloth wrote, running out of power during an update can be risky. Initially GrapheneOS A14 updates consumed a lot of battery power, in part due to an upstream bug that has been worked around. Updates may still be consuming more power, so some caution may be warranted, especially on older devices. Setting the updater to prompt before rebooting provides an opportunity to charge the battery and/or provide external power as the update takes place.