I have not thought of a scenario for double combos in our enterprise.
However I have thought of several places where it would be useful to
have combos on *yellow* or combos that could return yellow.
ie, go red if more than two servers in a cluster are yellow (solved
this one by creatng a second, duplicate local test that just reports
red when the original test reports yellow, used only for the combo
test, not itself paged on)
OR I want to go yellow if two servers out of four in a cluster are
yellow or red (haven't got a way to go yellow on a combo test)