The problems I see with this design are :
1) A dowel pin hole should go down at least as deep as the diameter of the pin, for solid location and strength. If it does not the hole will bell quickly with normal use and stresses.
2) If you tap a pin down into them and hit that top thread a little, the thread will bend down quickly rendering it impossible to use with a stud.
3) If you thread a stud down all the way to the bottom so you are sure to have a good grip, you will bottom out the stud and warp the plate if your not thinking about it.
4) Think about putting a stud into it and using it for clamping, how often does the stud stay straight and vertical when you tighten it? Each time it has to bend a little your trashing your bore because its the same size as the stud.
5) In good designs that are similar to this the bore is bigger than the stud and has a bushing to protect it, example: 1/2″ stud should have a 5/8″ bore with a hardened and carburized bushing to protect it. That would be an acceptable design.
After 30 some years of designing, building, using, and maintaining flexible modular fixturing hardware our opinion is: Poor Design.