Surely the expected solution for that is a UPS on the POE switch?
Ummm..... So the solution to cameras taking several hours to take back to life is to.... just to make sure the will never go offline?
The UPS remark is such an non sequitur. Sure, it's prudent to have one but this doesn't make the bug go away.
A UPS is not a solution for all power outages, just ones short enough to last the UPS uptime. The brains of the system is supposed to be the Cloud Key anyway which has its own built in “UPS” and seems to shut down gracefully if you kill power.
The cameras and viewports should not be writing data at all after an initial configuration if designed properly and killing power should present no problems to any system with a read-only filesystem. As someone who designs systems like these it absolutely baffles me.