Its not really a gray area. The Japanese had collected hard data. Their findings indicated that a V/L/V layered system like that of the North Carolina (KGV was similar) or like the German design* worked equally the best. The Italian Pugliese cylinder design was the largest per hull volume although the Japanese didn't test it.
Gray area being did a v/v/v allow the ability to counterflood more effectively, and if so was this enough to counter the v/v/v not being as effective as a v/l/v to reduce shock.
The main problem was the rigid lower belt could not deform to help absorb shock. And South Dakota did demonstrate a vulnerability to the shock of its own guns firing to knock out its electrical power.
I think it's a known that this was a concern, but the Yamato class had this same issue. Bearing in mind they took 12-20 torpedoes (and bombs) to sink, it seems in the overall scheme of things it was not as big of an issue as it may have thought to have been.