So I pushed the routing question again and this was the response:
as long as you are on a BA marketing flight in Club World or First and completing a round trip there is nothing wrong with either of the above routes
Good news for those of us who want to book a quick RT US-LHR-US.
This is good to know; I have an open-jaw planned JFK-LHR-DUS xx ATH-LHR-JFK; nice to have another data point that these still count as a "round trip."