Not much thought about how to score a Go game shows you that it is very difficult and I despaired until I read this fascinating paper by Andy Carta. After that I knew I couldn't construct the code! The paper was probably written about 2018 because that's when he published his code on GitHub here. It's over 2,600 lines of VB code. I took the VB and built it as a DLL so I could use in my C# program. Then to get the full benefit I (helped by CoPilot) translated it to a C# class. If anybody wants to use that, it's also on GitHub here (3,300 lines). It typically scores a game in under a second, when built in release mode.