Usually not much of a problem, but I would stop thinning that close to the tip. I would rather add a thin strips of wood or bamboo in the middle and narrow the width of tip sections, on both ends. If you are going to add tip overlays long enough, you can do that instead. If not, just watch out for the depth of the crack. It it turns out to be a full radial crack all the way to the back, you probably need both the overlay and the underlay.
