Have you tried the pvc? I’m wondering if it will be stiff enough to maintain tension on the blade and not distort in the center under pressure. The aspect I really like that Mors advocates is being able to not carry the frame and make one when you need it. I bought 36″ blades because I can carry the blade in a belt and not have it overlap when fastened around my waist.
74, I’d almost forgotten about that project. Time to get out my trusty SAK Swiss army knife and give it a try. I wouldn’t use regular Pvc for water lines but instead use grey electrical conduit stuff. The sak has a saw, a knife and awl. If I can’t make somekind of buck with really simple tools the idea wouldn’t be very useful.