I cannot find anywhere what new ZFS feature flags are added in what release, this is pretty important info when deciding whether or not to upgrade the pools. Please provide me with this information, and publish it so that others can see.
The zpool-features(7) man page will provide you with information on how to identify pool features that are available. They are not listed by release they appear in, as the man page is taken from upstream. The information can be retrieved from the FreeBSD src repo. The available zpool-features added in that release were not listed in the release notes for 12.0 due to an oversight. We're sorry about that. We cannot change these notes after a release has been published. I'm closing this PR as there is no further work needed.