I don't think they're doing duets anymore - those duets you linked are from two years ago.

It definitely is easiest to look up the current "simple" blends through the Lunacy page though. I agree that the series has been really nice - I've had some success with the more "complex" BPAL blends but I've definitely been buying less BPAL overall. A lot of their seasonals will have a collection like that too (like Cranberry Bog or Chocolate Box) and I've mostly found myself going for those over something with 6+ notes listed.