It would be helpful to be able to mark student assignments with "Extension" in addition to the existing categories with which they can be marked ("Collected," "Exempt," "Missing," etc.). Bonus if there can also be a fill-in box with the duration of the extension.
Because an extension that a student has asked for and been granted is a separate circumstance from late work, or from work that is turned in on the originally assigned due date, it would be nice to be able to keep track of it in the LMS. It would also be helpful for teachers and advisors to be able to observe patterns in students asking for extensions.