If a user does not have rights to the Document Type to which a document belongs that is in Workflow, the Save as New Document button is disabled in Workflow. If you want to create a new document under this circumstance, use the DOC - Copy Document action.
Likewise, if a user does not have rights to the Document Type to which a document belongs that is in Workflow and the queue the document belongs to does not have the proper Override Document Modification Privilege options selected, the Save as Revision button is disabled in Workflow.
When documents are checked out to the EDM Briefcase, Workflow actions are still executed upon them.