With the new feature that you can make your own statuses, I have created different ones, where we first have internal review, and then client review. However, it will be nice if we can create some sort of automations that the client will receive a automated notification or an email when something is ready for them to review.
What will make this feature even better is, if the automation can let you select a day, or amount of posts that have to be ready in order to send a notification. In this way as an agency we can stay flexible and don't bother customers for every piece of content that is ready, but only when multiple things are ready to be viewed. In this way an email notification can be send once with all the content that is ready to be viewed.