Came across an interesting quote from an old timbering book. If a square set is standardized at 5'4" c/c and 5'0" c/c, then the ore stoped out to allow for the timbering is 24 tons. It gives you a rough estimate of production, from a miner's perspective.
I really see the functionality being amazingly adaptive to an ore body. Jeez, the size stopes they made with them in Comstock and Rossland up in BC are amazing. Well, with back filling with waste rock of course.