Brett, those baskets and frames are the things I am interested in. I just wish I had the skill to make them and knew where to find the bamboo materials. Those bamboo groves that you see in the countryside all over the place are private property and you can get in trouble if you take bamboo without asking. Do you have any photos of the sawanobori gear and climbers you saw? I'd love to study their designs and see if I can learn to put together my own designs through them. However, bamboo-work is a real art, like woodworking, and takes years to learn well, so...
One idea I've been playing with for some time is to use a basket (or mesh) outer pack, into which you insert a very light drysack. The basket will then act as one huge outer pocket, frame, and protective surface for your gear. All you do is stuff gear that you normally would put into the outer pockets, between the basket and drysack. But since the bamboo frame has a form (though it can be quite soft if you use thin bamboo weaving) all you would really need to do is keep vital items protected from moisture inside the basket. Everything else would drain and dry quickly.
There is a lot ultralighter can learn from sawanobori walkers. Though the sport itself is quite new, climbing mountain creeks and the accompanying gear that is used has been used for centuries by mountain fishermen and people like wasabi farmers and mountain edible plant gatherers. Sawanobori walkers have long used tarps for camping and their gear is especially suited for very wet environment climbing (for instance some people use felt-soled fishermen shoes for walking in the creeks).
Speaking of traditional gear I saw a program by British bushcraft specialist Ray Mears in which he visits the Sami of Norway. One of the traditional Sami reindeer herders who spends most of his life outdoors in the Arctic, told Ray that he never uses modern insulation (like wool) for his footwear. He said it tends to sweat too easily and hold too much moisture. So, though he uses Gore-tex for his jacket, he still prefers to use traditional knee-high mukluks stuffed with hay. He said the hay does a much better job at keeping the feet warm and dry. I always thought that traditional Japanese reed snowboots were silly, but now I'm not so sure. Also, traditional Japanese raincapes made of straw (like roof thatching) were supposed to be superb at keeping rain off and breathing extremely well.
And there is the recent discussion about George Mallory's Everest gear
So much to learn from the past, when people spent much more time outdoors than we ever will.