This is a late comment to this thread, but will maybe spark the discussion again. As an MSP, I have customer contracts that involve billing for disk space. Currently there is no way to aggregate and alert off of a single datasource, such as WinVolumeUsage. I don't particularly care how a customer uses their allocated space, but I do care when they cross a threshold, as that would result in a follow-up process for my accounting team. And prior to them cross that threshold, I don't need to be manually monitoring the data manually, hence the request for alerting, as opposed to reporting.
