Proper C# integration would really help get a larger user base who may want to transition to Unreal if they could migrate their C# codebase. I assume this to be the case both with current Unity game developers and in other industries (eg Enterprise). Architecture field is used to a lot of tools being written in C# (eg Dynamo for Revit and Grasshopper for Rhino) therefore being able to re-use is critical cross software application - as you’d only need to build core functionality in C# to be able to port it into various design tools.
There is currently an active github repo implementing a C# integration. It requires a little setup but gets you there. Would be great to have some Epic dev support with this: