I think it would be helpful for students if there was some indication on the dashboard "upcoming" view when an assignment is complete. Either remove it from upcoming, put it in a new category called "completed", or place a checkmark or other indication on the assignment. Currently, in order to make sure we have finished everything and submitted properly, we have to click on each assignment and check whether it is submitted, and same for quizzes/tests/assessments. This can be time-consuming and difficult when students have a ton of assignments, and I am constantly worried that I missed something.
For submission assignments, it could check if anything was submitted, and same with google doc assignments. For tests/quizzes, it could check whether it has been completed. Some assignments don't require any submission, which I also think should be marked on the dashboard (maybe a symbol or word in the corner saying "no submission needed")
Overall I think this is a very positive change and a simple improvement that will have quite a good impact for how small it is. I do not know how hard this is to create, but please include this feature. I know it would really help me and I think other students feel similarly.