After using canvas for a year as a 5th grade science teacher, I've noticed how it is easy to miss significant trends in student performance. Once upon a time, when I used a pencil and paper gradebook, I could see each class on one page and easily tell where there were issues with individual students or individual assignments. As there is a bit of "scrolling" to do to access all of the data for each class on Canvas, it's too easy for me to completely miss a student who has several assignments not turned in or who is consistently getting lower grades.
I think it would be really helpful to have an optional alert notification feature. It could be accessed through the "Settings" menu, and it could be customized with several drop-down boxes. For example, a teacher could set an alert to be sent to his email when a student is missing more than 3 assignments. Or, another teacher could set an alert to be sent to her phone when a student has made 2 grades below a 65. A customized alert feature such as this would be a game changer and really help me as a teacher to be able to communicate even more efficiently with my students and their families.