To answer your curiosity, the PWM in the PicoLog1216 has a duty cycle that is adjustable from 0% to 100% in 1% steps, during setup, but the duty cycle can’t be altered once it is in operation.
To answer your question regarding getting started using the SDK, we do have Basic.Net examples non Github, and examples using Visual Basic for Applications that run in Excel, however, due to workloads, these haven't been updated in years, and we just don't have the resources to support them (I'm aware of at least one problem in the VBA example that we have on Github).
So, my advice (if you don't want to deal with the learning curve of moving to C++ from Basic) would be to look at our Python implementations. Python is simpler to get your head around, has many free resources for it, and will have the benefit of a familiar fast-track method that you can use to get up to speed, i.e. it lends itself very well to intuitive interpreters (like Basic did) which you can easily find online and use, also its libraries are pretty extensive (and also free).