Thanks! This worked for me (domestically).
Thanks for this post. I was able to get an otherwise unavailable all first-class domestic "round trip" for 45,000 miles on the dates I wanted. I did the multi-city search for coach. Chose an alternate return segment origin (40 miles from outbound destination airport). When availability came, I changed my outbound to first class using the calendar and found a "Low" award. I kept my return as coach, and when I got to the return flight results, at the bottom of the page were a whole bunch of First Class options that were NOT available using a traditional round-trip search. Thanks guys!!!