The deupdcached property is extremely expensive to retrieve and is hidden by default (if you try to run zpool command). However, py-libzfs is retrieving this property by default which is going to be very painful. We need to not retrieve this property by default and only make it be retrieved if someone explicitly asks for that property.

To retrieve this property via the zpool command you have to run zpool get dedupcached explicitly. Not even running zpool get all retrieves it.

NOTE: The UI team is NOT using this value.