Hi @Ray Crawford , thanks for using the Percept DK and sending us your questions.
Currently the only way to reset the device is to USB flash it. You can find those instructions at https://learn.microsoft.com/en-us/azure/azure-percept/how-to-update-via-usb
Regarding the "root" SSH user, we had that user enabled with some of the early private preview dev kits, but it has been disabled in later updates. The setup experience (OOBE) allows you to create an SSH user that you can use going forward. The Santa Cruz documentation is targeted to those early private preview dev kits, which is why it is mentioned there.
Thanks!
Mike McCoy