I eventually got the Illuminati32 to flash the firmware but I managed to brick it in the process.
When trying to flash the firmware of the Illuminati32 using Cleanflight I kept getting STM32 timeouts. I experimented with various manual baud rates etc. but It evenually came down to a timing problem.
When the Illuminati32 first boots up you get a green flashing LED. After a while the red LED comes on and the green LED is steady for a few seconds. The green LED then gets brighter and goes out, leaving just the red LED lit.
I was waiting until the green light went out before starting the flash process and constantly getting the STM32 timeout. I tried it once while the green let was in the steady lit state and Cleanflight reported that the firmware was flashing OK and then showed "Successful". At this point both the LEDs went out on the Illuminati and it hasn't worked since!
If I boot the board in Normal mode (Switches 1 & 2 on all others off) I get the blue flashing light but if I boot in FC Config mode (Switches 5 & 6 on, all others off) I get nothing.
Watch this space...