I appreciate you showing methods that you made up. unlike others who buy tricks and replicate them . having that said you might be over complicating solutions. I think this trick is simpler
Put a rubber band at the bottom to connect the two loose ends. It will keep the ribbon in the box straight. The moment you cut the ribbon the rubber band will pull the ribbon to the bottom.
Excelente como siempre en la fabricacion de cada caja de magia, me encanta la magia y la mecanica que hay detrás de cada caja magica, los mecanismos, la construcción es una obra de arte e ingeniería, Éxitos y ansioso cada vez en espera de un nuevo efecto magico mostrado por usted. Gracias, excelente Canal
I enjoy building magic props but when I've built one I never want to build another. I keep the original for my collection. So I'm sorry I can't help you, but please feel free to build your own.
SPOILER ALERT: After seeing how you got rid of the cut pieces of ribbon, I went back and watched you do the trick again. Knowing this now, you can see one of the cut ribbons being pulled before the front of the box is closed. I knew the other part of the trick already. If you pay attention to restoration tricks like this, you will see the restored item gets longer. If you carefully watch the sword through a person's body trick (the one you can see their body, not the one they're inside a box), you can see the sword gets shorter.