You do not get the “reason” for the CCV 8ft of height because you do not use the upper area for sleeping. The CCV tops provide 38” of height above the 3” cushion.
Having spent about a year sleeping up top in a similar setup (when the boys were younger and refused to sleep next to one another without us getting sued for copyright by the WWE) I can completely agree with you. It's crawl in Army-style, fall asleep, smack your head off the ceiling when you wake up and forget that you're in miniature clubhouse, repeat nightly...