@ari hey, your translation seems correct 🙂
Pi5 is supported by linux thanks to Pi foundation and their special kernel and BCM2712 specific patches. If you want to use mainline, you'll miss features.
As of BSD, good luck with finding some at least booting on Pi5.
Rockchip has way better mainline support and thanks to EDK2 you should be able to run any generic arm distro (I have to test this yet). BSD heavily relies on EDK2 and afaik you should be able to run some of it on Rock 5B quite well.