RN316 Stuck at Booting 99% immediately after firmware update

Advice for anyone landing in this situation.

1) Don't get emotional (My first mistake) And, use another computer to access your shares and, offload your data to other systems. DO NOT DELETE the data from the NAS. It might still come back after step 4.
2) Make yourself a USB boot stick from the instructions located here. Just in case things go pear-shaped
BUT,
3) First boot your RN3xx, RN4xx, or RN7xx system using the "reset button" boot procedure located here.
4) From the boot menu, select "Reinstall" of the OS.
5) Once restore is complete, try to log in.
5a) If you can log in, immediately restore your network settings. IMPORTANT: If you were using STATIC settings and/or a link aggregation, I would choose a different IP address than the one previously used.

6) If you LOST your user account(s) AND can remember your UID(s), try recreating your User Account. In my case, my data was still there after these steps. (I just happened to remember that my UID was 101.)
6a) If you just cannot restore access to the admin system, use that handy little USB restore stick you made in step one and use it to restore the system to whatever version you chose during the USB's build process

7) OK. After this, hopefully, you will not have the admin account LOCK problems that I had. I believe this was due to other devices on my network trying to log in repeatedly. So, make sure nothing else is trying to access the server. All they have to do is fail 5 times and you are locked out. (That's why I decided to change the IP address of the machine) This is ultimately how I managed to get things back to working properly.

I know there are quite a few having problems with the whole 6.9.x --> 6.10.0 firmware update drama. But, while your mileage may vary, this is how I finally got it done.

Hopefully, this will help someone else.