Warren in Lancaster, PA
Fantastic? Maybe you have never used a holdfast enough to show wear on the hole in the bench. Maybe some who read this will be on to their next bench before any great amount of use. We have had this discussion before; here is a solution that Paul (NJ) posted on this forum years ago:

Paul could have thinned down the arm even more. Roubo says the whole arm should be tapered for more elasticity and that it should taper to two lines at most (deux lignes d épaisseur au plus ). Two lines is .167 inches, which is less than 3/16.