I jumped the pre-slider version of the Paradactyl, & the opening was... memorable.
Fun though. I liked it.
Francis Rogallo's kite patent was for a "soft" design without a rigid frame.
I recently discovered the kiteboard/snowkite world that evolved while I wasn't looking.
There are 2 parallel design threads, ram air kites with tech crossover from paragliding, and leading edge inflatable kites with a range of aspect ratio and # of stiffening struts. Dacron & other synthetic materials, with polyurethane inner tubes.
There are videos of snow kites ( wearing skis or snowboard, and using a kite to go Up a mountain, or across fields & frozen lakes ) launching off mountains and gliding down. The "funny" part, is the harness/controls are designed to be used standing, not flying, so they glide with the "pilot" facing opposite direction of travel.
I'm tempted to get an appropriate sized kite and convert it to paragliding controls & harness, but the "regular" paragliders are so good now, it would just be for the learning experience. Otoh, a 21sq. Meter wing might be a hoot to soar the local training hill.