A lot of these ARM boards use custom (read: outdated) kernels and proprietary boot methods, so I'm not really sure how applicable they are to people developing Linux distributions that work everywhere. NixOS, for example, is only supporting UEFI booting on ARM64 going forward. If Redhat has the same policy, then there is only a limited set of arm64 boards available. I researched this recently as I'd like to move my k8s cluster from renting expensive cloud machines to running them on cheap machines at home, and the situation is ... difficult. (I have tested the Orange Pi 5 Max and the Radxa Rock 5B+. Both required me to hack edk2-rk3588, but they do work well now that most rk3588 support is merged in Linux 6.15/6.16-rc1. But, this is an old CPU and is just now getting mainline kernel support, and that is always how arm has felt. It is, however, kind of neat to see a "BIOS" on an ARM board. I hope it catches on.)