On the mechanical brakes I've used there's no doubt that the overall performance was far better when the fixed pad has a very light scuff sound. We're talking hardly any at all mind you. Just enough to know that there's zero gap but not enough to slow anything at all. When they were set like that the lever feel was instant and flex free.

And when set with just barely any scuff it's not long before the pad wears just that hair's worth and then it's quiet.