Give me something like Talos2 with a full OSS firmware and a performant CPU... and hell, a half-competitive open source graphics core too. It doesn't need to be peak performance, it needs to be good enough.
I've been trying to work with SBC's for a while for video decoding platforms and just wound up getting stuck on x86 because the ARM situation with weirdo custom kernels for anything useful is just... annoying.