For example - if students write an exam, can their papers be uploaded into Canvas for grading?
While it is true that if you have students upload files to an assignment, you can bulk download, annotate, and then re-upload assignment submissions, unfortunately you cannot bulk upload files for students that have submitted in class or on paper. There is an existing feature idea submission that did not receive sufficient votes to advance in the prioritization process that you can read more about here: Teacher should be able to bulk upload scans of "submitted on paper" assignments.
I hope this is helpful!
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