I have a different Motherboard as you and I need to test if everything works well (I doubt BT + Wifi will work) but I really do not care as this station will replace my 6.1 12C MacPro that can't handle 6K and 8K RAW video.
Anyway, I have however two questions for you.
1. I can't boot without the OC USB Stick in the computer, do you have the same problem? Do you know a solution?
2. I could not formated the SSD without having an annoying small partition, do you have the same problem?
That was the Drive for the EFI... I put everything there and now it boots without the USB drive. Now I need to find if we can hide this drive or not
Again, thank you very much for your guide.
Ryzen 9 3900X
AsRock X570 Creator
64GB of RAM DDR4 3600
Vega Radeon 64
Corsair NVMe Gen4 PCIe M.2 SSD 1TB Force MP600 series
macOS Catalina 10.15.3