Alert for Metric - Notification Grouped v. Separate, no difference?

So I have a Metric alert configured and working, it returns 2 timeseries ({{NumQueryResults}} is 2), but I cannot get it to send them as one email regardless of which of Grouped or Separate is selected.

Is that not what Grouped v Separate is for? In both cases, {{ResultsJson}} only contains one timeseries. I would expect {{ResultsJson}} to be a list, when Grouped.

That would of course beg the followup, if it was a List, how would you iterate it when creating the email message?