> If you can't map things one to one from a different program or close to that through a plugin

I've only used Godot in a hobby context, but the full on C# support compared to other engines is pretty amazing. Just as a proof of concept I imported an open source C# library I've worked on that's designed to play old DOS music formats, created a small wrapper node with control functions, and I was able to control it as expected from within GDScript nodes right out of the box. Only issue I would have seen down the road would be cross-platform compatibility since the library itself was Windows only.

Caveat: I can't say I've ever got far enough in Unity to say if the C# support is of a similar scope. Godot just "clicks" better for me, so I've gotten way farther with it than anything I've done in Unity.