I have been thinking about changing my hive set up and thought I would run it by yuall to see what you think. I know it probably wouldn't be for people with lots of hives. I would make it similar to a TBH, in that it would have 30 frames long with Langstroth frames. The last 10 frames would be a honey super, and you could place other honey supers on top of that one as you do now. It would make it easier to check on your brood chambers, not having to take the entire have apart to get there.
Make the BB and sides the length to accommodate the 30 frames and the tops to cover 10 frames. You could make them to fit whatever size frame you would like. An you could make the honey supers a different size with a little modification. Well that about it.