I bet there aren't. They'll need the back side completely flat for the heat sink.
You can see some examples in the EU thread:
https://bitcointalksearch.org/topic/m.3031271
(although their boards are likely slightly different, but the point is the same - you need it as flat as possible)
Here are some more images:
https://dl.dropboxusercontent.com/u/20909492/IMG_0069.JPG
https://dl.dropboxusercontent.com/u/20909492/IMG_0070.JPG
https://dl.dropboxusercontent.com/u/20909492/IMG_0072.JPG
https://dl.dropboxusercontent.com/u/20909492/IMG_0073.JPG
The circuitry seems so much more simple than BFL's stuff. Which is a good thing, imo. Maybe, I'm missing something.