Your product line has grown increasingly sophisticated over the years, and this external rendition is no exception. I applaud your creativity and persistent development.
As a user of a McHale suspended K2 frame (heavy by UL standard and comfortable carrying considerable weight), I maintain a bias toward hip weight transfer and a relatively circulated, dry back while trail hiking. This frame looks quite comfortable.
I appreciate your ( and others, as documented in past forum discussions of external frames) effort to transfer weight toward the sides of the hips, and was struck (by comparison to a McHale) with the fastening of tube to belt. An old video from McHale Packs shows a frame member fastened to the belt via a heavy nylon tab sewn to and hanging from the bottom edge of the hip belt. I think this fastening mechanism was unique to the heavier CM series packs, and the frame/tab connection occurred more toward the back of the belt. There are obviously differences, and certainly more that I'm unaware of. Nevertheless, I was impressed by the tab, hanging from a belt that seemingly retained its flexibility in contacting and wrapping around the hips.
Given design issues between the CM line and your external, I can imagine frame/belt fastening differences, but I would be glad to send the explanatory video if Mchale no longer uses it, and/or if you have not seen it.
Nice work, Bill.