Many of the instructors at our institution will attach feedback files for their students, often containing more detailed annotations than the SpeedGrader currently allows.
It would be great if those instructors could track whether a student has downloaded these feedback files for viewing. For example: an 'eye' symbol next to a feedback file could indicate the student has downloaded it.
This doesn't guarantee that the student will have opened the file, but in many cases it would help an instructor tell if the student hasn't even looked at their feedback. This would be useful for examining their engagement in a Canvas course and could provide further context for the student's progress.