I just wanted to report that I couldn't find an SDK/Library written for .Net; so I created my own and shared it with the world to help contribute to Phoenixd and the Bitcoin/Lightning community.
If you're a developer and want to use Phoenixd in your .Net application, feel free to take a look at my project and NuGet package.
Project: https://github.com/KredoKodo/PhoenixSDK
Nuget Package: https://www.nuget.org/packages/KredoKodo.PhoenixdSDK)
Have a great day! Stay humble and stack sats!