I learned to make the 3 hole bridge from Jose Romanillos in Spain. All 3 holes went completely through our bridges. The blind hole is an interesting touch. I did make a couple, just 2 I think, uke bridges with 3 holes, but it's overkill and I just went back to the traditional classical design. Interesting concept you have though.
The half hole isn't anything I thought up. I actually found out the way you mention 3 holes going all the way through with no string on the top after i had made this bridge. Your way sounds ever better as there isn't any string on top of the bridge. However there is an exposed string end. Either or.
It's just for aesthetics and the classical guitar hand position (and uke position) means it isn't really a problem (unlike say a bluegrass flatpicker who rests their hand on the bridge) with the string feeling like a rough surface under the hand. Still- it looks nice so i do it.