If I understand the geometry correctly, a solid 180° turn looks like a flat U shape, but you need a U shape with a 3D twist and a change in altitude along it.
Perhaps eliminating the solid borders along the middle section of the U will allow the living hinge enough flex. The ends need solid borders (and maybe a solid end plate) to join the rest of the track, so you must splice / join / weld those sections onto the end of the bendy hinge.
I finally figured out how to copy the quote. Can you make a how-to video for us. I think this is something people look at and give up. I think if we did an offset around the edges, and then did the cut lines as you did, it would work. It’s just the cut lines going to the edges, and the no cut lines that go to the offsets lines but not to the outside edge will have to be manually scaled to make it work correctly on the inside and the outside edges. With the straight track pieces, that’s what I have to do, so I know it works, but I cannot figure out how to make them go around as you did in your image above - which, by the way, is really cool.