It would be helpful when a due date is assigned that this original due date is somehow noted on their user transcript. If you change a due date when assigning a course, the only due date reported is the most recent one, so you lose any previous due date records. The only alternative is to make a copy of the course and assign that copy to a different user. This feels unnecessary and clogs up the Course Library with redundancy and potential confusion in the long term. I have been told the only way to achieve this is to go into a user transcript and manually adjust the due date one by one. I don't have the time to do this for every single course.