Is there a "best practice" regarding the depth of fret slots? That is, should they be, for example, at least .02 inches deeper than the length of the tang on the fret wire? And, what is the maximum depth of the slot that is acceptable with a radiused neck? (Referring to the depth in the center of the slot, where it would be deepest if slots are initially cut on a flat fingerboard)....or does it matter at all? (assuming you don't cut through the neck!) Thanks!