And still this is NOT a factory reset

It is just a way to Force the Atem into bootloader mode and wait for new firmware.
It does NOT reset anything as it often just keeps its settings from Save Startup state as they are loaded after the reboot
A few people are mistakenly calling this the Factory reset.. But it is implemented to get a corrupt firmware unit that is not running OKE to get into bootloader again to reflash it's firmware..
So stop calling it Factory reset!!
And no BMD does not have a Factory reset mode / button / feature.
So tell us what is wrong with it that you need a "Factory reset"???