With all the talk about tbh size, production, supering, etc., I added the plans for a Jumbo Combo Tbh to my website. This is a combination of ideas from my tbh and my combo long hives. It is rectangular. It has the depth of my tbh. And if a rabbit is cut in the upper edge of the long sides, it will accomodate standard length frames and equipment like supers, excluders, etc.
If this hive is to be run as a tbh, a 3/8 x 5/8 strip of wood should be tacked into the rabbit to prevent the bees from depositing propolis there. These strips could be easily removed and standard equipment put into this hive. Or custom frames, that would be much deeper than deeps could be built.
I haven't built this one. But it would be an interesting and flexible hive to play with...errr...test some ideas about product, comb depth, etc.
You can see it at the bottom of this page: