Consider adding warnings against using ZFS native encryption
github.com
github.com
And to be fair, almost every file system will have degraded performance and increased fragmentation above 80/90% full, so this should be considered universal advice.
There is also a legitimate question of how wide spread the issues are with the ZFS encryption feature. The fact this hasn't picked up much steam implies its not a common issue.
Ext used to reserve 3-5% "for root", but the reality is that you're supposed to free up space if you let it get that full.
best comment that summarizes the issue for me at least:
"I personally am just treating the native encryption code as unmaintained at this point, though, and would advise most other people do the same."