It's looking like FP9 is a little bit bleeding edge isn't it.
Also, there's a longstanding limitation within Domino for trying to do just this thing with the ViewEntryCollection call. So I would also be interested in whether this new call returns all documents under its results; or if it only returns the first one.
And of course I wonder whether they revoked the feature when they realized it had that limitation (which was introduced in R5).