Started work on the seatpan, towers and adjustable leg-lifter over the extended weekend. Rather than using straps, the leg-lifter is supported and raised by an oval drum that has an off-center pivot point. The leg support can also be lengthened. It's all fairly simple and uses few parts to accomplish the goal of properly supporting the paddler's legs.
Once I have everything dialed in, I'll go back and start perforating areas of the leg-lifter. Looking at some of the chairs in the Herman Miller collection for inspiration. There will be a pad placed on top of the seatpan.
After all of that is completed, I'll start work on the adjustable seatback. I've already worked out how I'm going to raise and lower it. Going to use a 4-bar linkage system similar to that found on mountain bikes. There will be a small ratchet buckle in between the paddler's legs that will be used to raise and lower the seatback.