I had the thought that if he sewed on a flat piece of around 7/8" to 1" grosgrain with one of the magnets sewn in the end by doubling the grosgrain over and making a pocket, it would hold very well. When those little guys get together, they are amazingly strong! There is enough play in the hem that the magnets could be flipped as needed to keep the polarity right to keep them all attracted to each other in sequence. I bought some 7/8 grosgrain when gathering materials for this project in case I wanted to run it along the edges, but I didn't think it was needed. It seems wide enough to do the tabs for the UQ.
One great thing about this system is that since the two layers aren't sewn together, they don't get extremely tight(unless you make it) when you climb in, and the insulation does not seem to want to skid around under that pressure like in a standard DL setup.