The BIOS chip is a Macronix 25L6473E , it's not specifically listed in the manual as being supported, but I'm guessing it is:
Getting over Hurdle #1, loading the new firmware (Done!) - Took some time to find the damn firmware ...it was in a folder included with the software and using the bootloader procedure took some careful instruction reading. Thanks to
@silentbogo for adding that post.
Hurdle #2 Connecting the FlashCAT to the motherboard (Still working on this one)
Problem: When connected to the MB, the FlashCAT is not recognized by the software
Mistake #1, Using the MSI SPI header and assuming the pin diagram for the SPI MB header applied in my case. My board has an 11-pin SPI header, there's an additional connection to be made to pin 11:
What I think I'm going to do - Use the direct "Chip Clip" method. The only hurdle is this will involve some soldering, as one of the pins does double-duty on the BIOS side of things (see red dots). I..E - the VCC on the FlashCAT splits off to
both VCC and HOLD# on the board.
@Solaris17 - did you run into this?