Thank you for this - we use the completion progress block, which works with the activity completion "Expected due date" and not the assignment module's 'due date' setting.
Also, students were getting confused seeing their assignments show up twice on their dash board (one entry for the due date and a second entry for the activity completion expected completion date).
So we decided for consistency, to eliminate the "due date" setting since it is not available in all module types anyways.