I am really sorry to interrupt you.
In the process of cleaning up old hard drives I found my take on the C# interface to WaveForms SDK (from year 2014) and put it up on GitHub, https://github.com/Andrei-Errapart/WaveFormsSDK
The difference is that I have taken the trouble to turn errors into exceptions, which some might dislike. Other than that it is also one-to-one mapping to the SDK.
The license is MIT, which is quite permissive - many companies use libraries licensed under MIT.