Basically the opposite of what I'm seeing you suggest, Tako. Unless I'm reading it wrong, you're saying to play doubles up to near the end, have the people who are still in doubles instead play pools as Wave 1, and then have the other group, those that weren't still in doubles, play as Wave 2. The only difference between this and my suggestion, from what I can see, is that a lot of people aren't going to want to switch back and forth between playing singles and doubles. And why should they, when the other option gives similar results (regarding time) and doesn't force them to.