if I recall correctly
If I recall correctly, the hinge is "holes only" un dimpled. The flap brace is countersunk and the skin and is dimpled. That's just from memory, but I'd have to look at what I did or the plans/manual to say for absolute certain.
I have heard that it's an acceptable practice to un-dimple, but I don't know about un-dimpling and then countersinking. Call Van's bout that one.