Hi David.
I've updated the post with instructions, on the opposing side of the SMA connectors CH0 and CH1, there are two pins on the PCB labelled VDD and BOOT0.
They need to be shorted with the powered off state, then with those shorted power on the device.
Sorry for the confusion.
Ps. I included the ssh key part as I could not "git submodule update --init --recursive" without a one.
Kind Regards
Ohan Smit
ZS1SCI
Ohan Smit