After going back and forth with Support (who were great), it has been discovered that only Assignments can be marked as done on the To Do list. Meaning that if I complete a quiz early, I am unable to mark it as done and remove it from my list so it still shows up on my Canvas To Do list widget until it is closed. It would be nice if we can mark anything that shows up on the To Do list as done. Another option would be the ability to choose what shows up on the To Do list. The widget is a nice feature, but it can get cluttered fairly quickly with quizzes, which is slightly frustrating especially when I have already completed them and want to see other items without having to scroll. I hope this idea can be implemented.