I'm working on a grade uploader and part of the feedback will be provided in a submission comment. I have no problems getting the grade and comment updated using the REST API. I would like to be able to have an "overwrite existing grade & comment" mode, but there doesn't seem to be a way to remove submission comment via the API. It can be done in the Canvas UI, but it's not feasible to go through and delete comments in SpeedGrader. Has anyone found a way to delete submission comments through the API?