2) It just blinked the Sony LED, but was able have the firmware be rolled back using Special Options
3) It just blinked the Sony LED, but required the "unbrick" hack to rollback the firmware because the touchscreen was unresponsive
I used a small cluttered FAT USB the first try and would get to the screen to restore factory defaults, update from usb, or update from network. I could choose network or restore factory defaults as my screen worked - but I could not choose usb - if restoring factory defaults it went back to being a brick with flashing logo and sony on the screen. I actually had a copy of update.zip on my server from 2016 which I used - the same size as a google docs version shared on this forum.
2nd try I slow formatted a 4GB Fat 32 USB - got to the three choices screen but because I did not hold it down long enough and my screen did not work so I could not select anything.
3rd try kept holding it down and it went to the three choices then after 10 seconds or so started updating on its own. The update was successful and I had the clock only with one alarm and no network.
I decided to connect to the network then download the control panel which still shows my default setup from the sony server. I then blocked the Dash from further internet connectivity at my router. It continues to work and under device info shows that Registration code "Failed" "19" It will continue to work it seems as a clock with multiple alarms, and my favored screen configuration until the power goes out - at which point when it can't connect to the internet it will go back to being a dumb clock with one alarm.
I would be happy if I could get my favored screen to live on the device and have it survive power failures or being unplugged without needing to reauthorize