A Phoronix reader wrote in that he believes due to his consistent requests of Btrfs developers is now this "Nouveau-like" status page for indicating the state of different file-system features.
The status page shows most of the features are okay while considered "unstable" is RAID56, Scrub + RAID56, and the free space tree. The free space tree is broken on big-endian systems while we've previously covered the Btrfs RAID 5/6 code turned out to be bad.
Features to be determined include seeding, device replace, balance, quotas, out-of-band de-duplication, and file range cloning.
Btrfs status details via this Wiki page.