That is the eventual goal. We deprecated Rhino_DotNet in Rhino5, but didn’t break anything. Now with Rhino 6, there are some SDK breaks that occurred in Rhino_DotNet. I may be able to patch up some of these breaks if I knew what wasn’t compiling/working with your plug-in.
RhinoCommon is where all of the enhancements go and is a much more mature SDK in general.
I can see where this can cause confusion and I’m sorry about that.
All that said, Rhino_DotNet will remain in Rhino 6 and you can use it in conjunction with RhinoCommon for a gradual shift over to being RhinoCommon based instead of completely cutting the cord all at once.