Thanks for the response! I definitely followed your advice from the previous post. I do get a flashing indicator on "0" when in this apparent, but unverified, bootloader mode. I went out to the store and bought a "mio" USB type A to 5 pin Midi cable to send this update via midi to the device. Is this what you meant when you said to send the update file via 5-pin midi?
For the bootloader mode, it might only work over the 5-pin MIDI port.
In your case, I'd have tried without the bootloader mode. If you're connecting over USB, ideally, the Pro 3 will be listed as a MIDI device (whether via SysEx Librarian and the sendmidi/receivemidi command-line tools). If it's not, then it might mean only the bootloader option is possible (again, just guessing). So, I'd power up the Pro 3 SE, connect the USB cable, select the Pro 3 in SysEx Librarian, and send one of the .syx files. Then, repeat with the other file. And, if that fails, try the MIDI cable.
As for the lights not lighting up when attempting with bootloader mode, that sounds like it not working. I believe I recall those lights lighting up during the load process. NOTE: that's only for using the bootloader mode. During a normal OS load, those lights do not light up; only updates happen via the display.
Of course, your best bet is support, if it doesn't work. But, if they haven't responded, yet, there probably won't be a response until Monday.