I briefly tried to make a midline attachable, using a very small Black & Decker battery powered screw driver. I gave up but still have the screw driver.
That is similar to the boxes that sailors in the days of old stored shot lines in to shoot messenger lines from ship to ship at sea.Took this idea from Nick Lewis, an arborist/tinkerer I got to work with for a while. His version was more durable and pretty than this. No wind knots, like, ever. The pegs are secured to a circular piece of wood at the bottom of the 5 gal bucket. The pegs keep the loops from folding on top of each other in transit. Works really well, but honestly, I just use the cubes since this takes up a lot more space.