There is a missing option pubsub#notification_type in the node configuration. It would be very good to have it there with the default value set to headline.

Thanks to that, notifications from all current pubsub nodes (ie. OMEMO, avatars, etc.) will not be stored in the offline storage or in MAM as headline messages should not be stored. Most (if not all) of those notifications should NOT be stored as they are based on +notify for an automatic subscription which causes sending of last published item when client comes online, so storing them in MAM and offline storage is a waste of storage and bandwidth.

If anyone would require to store PubSub node notifications it will be possible to change notification_type to normal in the node configuration, which will force notifications to be sent as normal messages and allowing storage of them in MAM and in offline storage.