Hello CaseySJ,
Thank you very much for the excellent guides for the Designare Z390! I have been running mine for some while without any issues! I am also using a Samsung LC34J791 display with thunderbolt 3 connection, which is working great!
My QNAP TVS-472XT won't connect using Thunderbolt, since it is using Thunderbolt Networking. So I have been following your investigation in modifying the Thunderbolt firmware. I tried reading my onboard Thunderbolt chip with a RPi 4, but I can't manage to read the chip, not even with your customized schematics.
I did however come across the following website:
Page 2 | Blackmagic Design released a firmware update package for the Blackmagic eGPU/Pro. What interests me the most is that it's for macOS. I downlo...
egpu.io
In that tread they have been patching the macOS built in Thunderbolt firmware updater. In this case to update EGPU firmware. But on page two they are discussing that it should also be possible to use it to flash the built in controllers/read built in firmware. Do you think this would be a viable option for a software solution?