Pop-up alerts about volunteers

I've had a couple of problem volunteers who haven't done enough to warrant disabling/suspending their volunteer account, but who should definitely come with a warning or pop-up alert.

For example, I have a couple of people who consistently sign up for a bunch of opportunities at once, but then will cancel with some of those opportunities on short notice, typically when they receive their automated reminder email a few days prior. It would be nice if, within their profile, there was an option for an "Alert Note" that would pop up each time I open their profile or I register them for an event on the back end of things as an admin. The pop up could come with a "Dismiss" option (i.e. close this window for now, but keep the pop-up activated) or "Archive" which would discontinue the pop-up and file away the note in their profile.

If the person registers themselves for an event, maybe there could be an indication of an Alert Note in their profile by showing an exclamation point on the "View/Register Volunteers" page of an event. I'm attaching below a mock-up of that idea.