Thanks for the answer.
So for any given configuration there will be customers who will tell us “if you would only increase the size of this feature then my program would run so much faster; pretty please with sugar!”. But as we scale any member’s configuration pretty soon we get to the performance of the next bigger member. So we’ll say “just buy the bigger member”, to which they will say “but that costs more money!”.
The best response to this is: “Not as much money as licensing the lesser member and having TSMC fab it with your specific changes.” (Well, if you are open to such an arrangement. Are you looking to be an Intel or an AMD?)