Just a small thing, but as someone who never actually played around with filesystems so far, I was looking to try out the changes outlined in Changes/BtrfsTransparentCompression, but the command on the page:
btrfs filesystem defrag -czstd -r
If you add the compression option to /etc/fstab, is the -czatd option needed here?
I'm going to try out zstd:3 for my spinning disk as I remember some conversation about that on the list a while ago.