In our school we try to educate students to be aware of file sizes when submitting work, preparing them for industry (vocational education). Though we note in our briefs and in class the maximum file size to be uploaded for an assignment (especially in the case of PDFs), many students fail to comply.
Canvas is a step better than blackboard as it allows limiting the type of file uploaded. It would be great to have a area to limit the file size as well. This way the student "learn" to read their briefs and comply, actually learn how to reduce file sizes, and at the same time lower disk usage space on our school drives (if we download) as well as on the canvas server. A plus for all.