Hi nice show thx therefore, you mentioned the linux kernel may handle the cpu setup better than bsd's. So iwant mention the slackware aarch64 which officially supports the pinebook, as slackware is relative bsd like (it uses sysv init instead of systemd for example) and you could get the advantage of the linux kernels hw-compatibility. long story short if you like to check it out here is the link: https://docs.slackware.com/slackwarearm:inst_sa64_rk3399_pinebookpro. It's currently only the current version but i run it on my rpi4 it's not broken till i ran it.
sunzu