Thanks Cheryl and Gary for the comments. Regarding brace comb, I don't have experience with a slanted TBH, however on Delchi's hive every frame had some degree of brace comb on both sides, and many were attached at the bottom. With two of us working with hive tools it was fairly straight forward to extract the frames.
Note the observation windows - pretty cool! But they also give idea of frame connected to sides by comb.