I think unsettled area during the game is a bit vague, and it’s probably fine if an estimator can give some points in areas that are a little uncertain. (Of course you don’t want that if you’re using this kind of thing in ranked games where you don’t want a strong ai opinion of what will likely be your territory.)
On the other hand at the end of the game “what seems reasonable to both players” is also a bit vague but I do have a suggestion:
- Let Katago decide what stones are alive and dead based on whether they are “pass-alive”, that is if their status hasn’t changed with the last two passes. Any remaining groups whos status has changed with the last two passes should be marked alive contrary to what katago would do depending on whose turn it is. That way it hopefully should reflect what the players believe since they both passed.