I was under the impression* that a command like 'zfs get all TANK' would return all the properties of the pool, along with a list of feature flags; this doesn't seem to be the case, however. Some features are in the list returned (like encryption), but other features like bookmark_v2 are not listed (I guess because they aren't things that you turn on or off for a given pool or dataset).
I know that 'zpool upgrade -v' will list all the features that the currently running zfs implementation supports. Is it just assumed that if zpool status doesn't list any need to upgrade then the corresponding pool has all of the offered features in play?
* here is where I got that impression: https://bsdmag.org/zfs-feature-flags/
"To see which feature flags are enabled in the pool, type:
root # zpool get all
Supported feature flags will be prepended with a feature@ and the organization name will be omitted. Unsupported feature flags will be prepended with a unsupported@, and depending on where they are marked as active or inactive , the implementation will not be able to use the pool (or use it in a read-only fashion), or just ignore the unsupported feature, respectively."