Currently, it is possible to set up a notification that will be triggered by the event "Form Response Field Note Added." However, only field notes that are visible to the respondent will trigger the notification; any field notes added that are not marked visible to the respondent will not trigger it.
This makes things harder for reviewers, both because they have to remember to check the box making the field note visible for the notification to trigger, and because in many cases it would be preferrable for reviewers to leave notes that are not visible to the respondent (e.g. "double check with student to make sure they have submitted ___ form") that trigger notifications to fellow reviewers.