In Updox one can edit, such as print time and date stamp, actual electronic signature, type letter/numbers, erase, free hand write etc. any of the documents. If outgoing from Updox, however, the changes will not be kept in AC, if ingoing to inbox into AC those edits are saved.
Perhaps I am mis-reading, but as Mel mentioned, the correspondence/secure msg you are sending out via Updox can be sent along to the record at the same time.
Once users realize that they can send the same document several different places at one time they get pretty excited to only have to touch the document once, e.g. referral to a specialist - the prior authorization comes in, it gets sent to the record, to the specialist, and to the patient through the portal.