I have an application that I need authors to keep author-level access when creating a document. They can open and edit their saved documents. But when the document is complete I am having them submit it to be approved but from that point forward, I want their access level to be “reader”. They can never go back and change what they submitted.
Simply remove them from the Authors field on that document. They must be in the authors field in order to be an actual author of the document, so by removing them, they will be a reader of that document. When they submit to be approved, you can include some code to clear out, or reset the authors field.