Yeah, mounting hole omission is for builds with non-standard mounting screw patterns. Whether or not you will find it advantageous depends on your choice of mounting screw pattern. For most people, it's a matter of matching necks to existing bodies, but for some, there is a desire for oddly shaped neckplates, in the interest of contouring the heel. You have to be careful with this, because Warmoth Pro necks have a side adjust mechanism that you don't want to drive a screw through.