'Best' AM4 mobo for Linux in 2021

[danboid]

I asked System76 where they're up to with this:

"At this time, we offer Coreboot on several of our laptop models and laptops with 10th...

[danboid]

I'm thinking about buying a AM4 socket mobo to mainly run (Ubuntu+Arch) Linux on. I am going to get one of the Ryzen 5 APUs at first then might upgrade...