I'm one off those people who likes to understand why and what for. I like to understand how a concept works and what the principal is, and then I create my own variation, my way.
So, other than the obvious, what is the principal and concept behind the "top board"? Do the bees not like it if there is too much or too little space over the top of the frame bars? Bees seem so adaptable in the wild, building in all kinds of strange locations, but I realize established techniques have been researched to optimize production the and well being of the bees.