This would always work in theory but I guess few, if none, have actually tried updating this way or at the very least outlining the appropriate steps. Just some things I wanted to touch on:
- The reason you don't need to press the power button after the system reboots once it is done installing the system update is because, well, it pressed the power button for you. Can't exactly boot into RCM if the console is off. Holding volume + is still required though as this is what determines whether or not the console will enter RCM (along with pin 10 being shorted)
- This goes to show how well made the TX jigs really are so they may be useful for those who wish to update this way, but the drawback is they are behind a $40 paywall whereas most other jigs are much cheaper. The success of this update hinged on how well their jig can short pin 10 so any jig/hardmod that can tout an equivalent success rate can be substituted
- The dongle is the least necessary step in all this as the console will stay in RCM until you manually shut it down or send a payload. The ironic thing is that based off what I just said about the TX jig, you will already have the dongle if you are attempting it with their jig. This makes this whole point more or less moot
As a final check, not that I have any reason to distrust you, but I recommend running
briccmii V2 in order to check that no fuses were burnt at all. If the number of fuses burnt is less than 6, than you updated correctly.