So the POINT of the hinge is NOT that it is "demountable" as the name states, and which I assume it is, although I can't for the life of me see HOW (without a screwdriver) and you guys DO say a screwdriver is needed, so I don't get the "demountable". And if I'm reading you guys right, neither do you but I may be wrong about that.
The POINT, if I now undestand it correctly is for the ease of adjustment and the only way I can see that this tab thing makes it any easier is if the hole that allows the mounting screw to go through the leaf and then into the tab is actually a SLOT and the screw is only grabbing the hole in the tab not any of the wood. This way the door can be adjusted up and down. Is that the way it works? Do I have that right? Could you even just make the hole a really big hole so that the door can be adjusted both right/left AND up/down before you tighten the screw into the tab?
I appreciate everyone's patience with me on this.
I'm going to say whoever told you that you don't need a screw driver was mistaken. The screw you tighten sucks in the tab and the tab has little shoulders on it that grab and sandwich the wood. And yes, if you make your slot a little bigger, you can just simply move the door itself to make the reveals even then tighten the screws down.
None of this silly open the door, quarter turn, close the door, look, open the door, quarter turn, close the door, smack it into the other door, swear, open the door, quarter turn, then find yourself back where you were.
And no, I don't know why "demountable" is what they're called.