I think you are missing a forum because my post is about Windows Store Development, but not about Metro apps.

Microsoft DesktopBridge compiles .NET apps for the Windows Store.

Has anyone had success creating UWP libraries, compiling those to native code, and importing the result into a .NET app?

Reason: When UWP code is packaged for the store it is compiled to native code. DesktopBridge skips this step for code that has a dependency on managed .NET libraries. I would still like to push as much code as I can to native libraries.