Subscribing to Automated Workflow Proofs

[#1]

Would be nice to be able to subscribe to an Automated workflow by either having stage specific public URLs, meaning that if you are in one approval stage and you share a public link to the proof it is a link specific to the that stage which could then allow for any subscribers with access to that specific link be automatically subscribed to that stage or have it automatically add the subscriber to the same stage as the person who shared the proof instead of having to acquire access by the proof owner.