redcap Hi, thank you for posting! If you have any unresolved questions that you need help finding an answer to, we're happy to help you at any time.
In terms of C# documentation; we don't provide documentation for the generic C# runtime or Monogame, but we do provide docs for our spine-unity runtime:
https://esotericsoftware.com/spine-unity
We also offer our Spine Runtimes Guide that provide information about the architecture and functionality of the runtimes we officially support. You can find that here:
http://esotericsoftware.com/spine-runtimes-guide
We also have our spine-godot documentation here, which has information that is relevant to setting up and using spine-godot with C#:
https://esotericsoftware.com/spine-godot#spine-godot-Runtime-Documentation
If there is specific documentation that you'd like to see written for C#, please let us know which runtime/framework you're using and we'll be happy to help.