Washing is a D’rabannan of Inui. Overstuffed would for sure not be a Mitzvah, because that’s not called an Achilah. What does it matter if you don’t like the food? Inui is determined by fullness, not enjoying the food. And by “being full” I meant not being so hungry. Maybe you would need to eat a Koseves in K’dei Achilas P’ras but I don’t think so because that’s not how the Mitzvah is worded. But it does bear looking into.
