Here's an idea: Let's taboo 'substantive'. I suspect that by 'substantive' some of you mean 'important,' while others of you mean 'concerning the extra-mental world' or 'carving Nature at its joints.'

So: Are we arguing about whether our criteria for saying people know or fail to know things matter? Or are we aguing about whether there's a completely human-independent 'fact of the matter' about what the word 'know' does, or ought, mean?

Obviously purely conceptual questions can nevertheless be very humanly important; they can be conceptually deep. (Even completely arbitrary issues of rule-picking and definition-choosing can be extremely important. For instance, it matters a lot that we all agree on whether to drive on the right or left side of a given road, even though it's fundamentally arbitrary which side we all agree on.) And, equally obviously, most joint-carving questions are not humanly important at all.