The founding developers were all software engineers with .NET experience, so it was the natural choice even though at the time it was Godot 3.x with Mono. I had used Unity before but not Godot. The project is structured as mostly plain C# DLLs with a relatively thin Godot UI layer controlling it, so the Godot type system is fairly encapsulated. We haven't really seen any issues with those decisions beyond just working out the communication between Godot and DLL. But again we were just working from what we knew so I can't really say if this was the best way to go about it.