The Dasharo FidelisGuard Z690 is a Qubes certified desktop:
Any experiences with ordering and using one of these desktops?
I don’t have the FidelisGaurd, but I have been running Qubes OS on the Z690 with Dasharo for 9 months, I have not had any issues with Dasharo.
Dasharo is the most user-friendly version of coreboot I have used, you don’t need to compile it yourself, they provide precompiled images, you don’t need an eprom programmer to flash the rom, it has a menu to configure the bios settings, and it can be updated over network.
FidelisGuard is shipped with the Dasharo Tools which makes it easier to update the firmware. You need to use flashrom to flash new firmware, the Dasharo Tools is a Linux image 3mdeb provides which can be PXE network booted, allowing you to do updates over network if your computer has internet access.