Correct, I had switched to BW from Jan, 11th to 15th when they were best and my results showed the correct expectation.

If you don't check daily the risk distribution might be a good idea. But I take a look daily at the Google-Spreadsheet as well as the Minerlytics Site and switch accordingly. As you said, the quality is usually consistent for at least a couple of days (mostly even longer). So being not on the top side for a day before switching should hurt less than consistently passing on the top results due to a mix.