Does a forfeit affect existing gold scores? For example, if a player forfeits, does their gold count, or does it automatically become 0? (asking partly since someone could have an “emergency” and clear their fleet out and leave the venue, at which point they can’t claim to win just because they have more gold at the time)
That’s going to be up to the group or whoever is running the event.
It can be worth noting how much gold they had when they had to leave just for the sake of posterity, but if it’s being treated as a forfeit, I wouldn’t give them credit for winning even if they did end up with the most gold.
If some sort of running total is being tracked from game-to-game, there’s also value in recording how much they had up to the point they had to leave. In a case like that, I think it would be better for them to show how much they had to an outside party or someone running the event before leaving, without revealing it to the other players until the rest of the game was finished.
Home island raiders throw a wrench in the works for any longer-term tracking, because technically the forfeiting player’s total could go down before the game ended, but the fact that they’re leaving early kind of assumes their final total would have ended up higher had they finished completely. How to handle disputes about that would be up to the group or the event runners too.