I really like the Save as a draft option in forms. However, even after the form has been finally submitted, the link to the draft still works. If the content is (or not) updated, if the person resubmits the form, it will create another entry in the board. This should not happen. Once the form has been submitted, the draft link should be blocked and no longer work.
In a nutshell, once the form is submitted, the draft link should no longer allow the user to modify the content or to resubmit. Only to view the data submitted.