Sometimes (often?) at your own peril!

To anyone else following, if you're mucking around with "I am Root/Admin. OBEY ME!!" you had better have important data backed up!

I once thought an unlisted BTRFS snapshot was an orphan folder taking up space. No permission? Nonsense! Obey my commands!

Suddenly not even terminal commands worked. ("Command 'cd'/'ls'/whatever not found")

. . . it was the "writable snapshot" currently mounted, and the system was so borked it couldn't rollback, and I needed to completely reinstall.

Fortunately I had things backed up on another drive. Live and learn! But that could have been TRAGIC.