We have been testing wdfcontrol with our application. We have been using version 3.1.18.1 of wpdcontroldemo.dll (this was emailed to us after we had some issues in the downloaded demo dll).
We are happy with our results and have purchased a license. The version of the dll that we got in the download is 2.6.1.3.
How do we go about getting a 3.1.18.1 version that we can use and distribute with our product?