I have this same question. In an effort to grade more equitably, I have flexible due dates. Ideally students have submitted projects before exams (and the due dates are such), however, sometimes this doesn't happen. I would like the most recent grade to be the exam grade. For some students I enter the projects before exams and for others the exam before projects (depending on when they submit). This could lead to a difference in each grade for students--like if they had a 2 on the project, but a 3 on the exam, the decaying average would calculate this differently if it is based on when I enter the grade as opposed to using the due date of the assignment.
HELP!!