Holy Frak I fixed it!
You were correct, there was some rudimentary version checking going on.
I'll explain how I figured out what change prompted the unit to reload the software and how I made it happen.
Proceed at your own risk. I cannot accept any responsibility for any damage caused by the information provided below.
I downloaded the BIN file for both the MiVue 538 and MiVue 568 (see above) and then used my trusty "0xED" hex editor app and the command line utility "strings" on my Mac to investigate what might be going on when a firmware update is presented to the MiVue 568.
My initial look at the BIN files with 0xED gave me a general "lay of the land" of the structure of the BIN file, but not much more. I then took 2 hours to look at all of the strings within the BIN file using the strings unix utility piped to more:
strings <filename.BIN> | more
and that gave me a few ideas of what the firmware upgrade functionality was looking for and I tried tweaking some dates and some other items in the BIN file with 0xED without any luck getting the MiVue 568 to accept the firmware update.
I then started looking within the BIN file using 0xED to see what was going on in the area where it was handling the SD_CarDV.bin file during a firmware upgrade. There was a lot going on there that I was assuming was file checking, but I wasn't exactly sure which items were being checked.
At this point, I decided to have a look at the was being created, albeit incorrectly, on the SD card by the wrong firmware that I had installed on the dash cam. The dash cam by default creates 4 directories named "Emergency", "Normal", "Parking" and "Photo" and a file called DEVICE.XML in the root directory of the SD Card.
Within the DEVICE.XML, there are a lot of potential items that might be used to trigger a firmware update, so I searched within the SD_CarDV.bin file for each entry.
Example correct DEVICE.XML file for a MiVue 568
To my amazement, the FWVersion, FUD, and ProjectCode entries in the DEVICE.XML file were not found. It was the SKUID where I started having some luck.
The SKUID in the broken DEVICE.XML file was 7127. This number 7127 matched an entry at the beginning of the BIN file for the wrong MiVue 538 SD_CarDV.bin file when I edited the file with 0xED:
Unedited MiVue 538 SD_CarDV.bin file
I held my breath and edited the correct MiVue 568 SD_CarDV.bin file and found the following at the same place in that BIN file:
Unedited MiVue 568 SD_CarDV.bin file
I then replaced the "7138" in the MiVue 568 SD_CarDV.bin file with "7127" that the wrong firmware was expecting and saved the hacked SD_CarDV.bin file with 0xED.
Hacked MiVue 568 SD_CarDV.bin file
Per the firmware upgrade instructions, I connected the broken MiVue 538 with the wrong firmware installed, removed all directories and the DEVICE.XML file from the SD card and placed my hacked version of SD_CarDV.bin in the root directory of the SD card.
Per the directions, I disconnected the USB cable, let the MiVue 568 shut down, and then pressed the power button.
To my excitement, the firmware update process started!!
During the 5 minutes that the firmware update took to complete, I was extremely anxious to the point where my wife asked me if I was OK.
After the firmware update completed, I gingerly pressed the power button again and to my total joy the MiVue 568 worked correctly!!!
I was so completely relieved and totally stoked that I was able to recover from my screw-up.
Hopefully this information will help someone else in the future.
I will follow-up with a stream-lined procedure for this fix in a follow-up post for those who don't want the drama