I don't see how this is relevant to the question of whether categories need precise or inviolate boundaries to be legitimate.

I do think you're already anticipating the next question that I was going to raise (which has to do with the first-person third-person distinction), but there isn't any point talking about that if we don't understand what makes a category to begin with.

So: do you agree that it is not necessary to be able to define a precise boundary between "chair" and "couch" in order for the categories "chair" and "couch" to have some utility?

Furthermore, since we're talking about perception of internal states for now, do you agree that "disappointed" and "angry" are also different categories, even if you can't precisely delimit a boundary, and can play a practical and non-vacuous role in your internal understanding of yourself?