It seems like the gradebook view could be redesigned to take advantage of some of the white space. If there is feedback, all it shows is a caption box. But what if it showed the beginning the feedback so that the student knew there were suggestions for improvement. They might see the caption icon and think that perhaps it says "Good job" or "Needs to be resubmitted". But if they saw the start of the feedback that says, "Here are some suggestions on how to correct problem #3......" the student might actually go in and read the rest of the feedback.