I think the sheers might work better than the work of moving them back and forth. For cane begonias someone gave me this method and I follow it. I have about 9 in strong morning light now, I plan to put them in our dark basement storage area for 3 days, then put them where they spend the winter and spring. I guess the theory is they will be so grateful for light when they come out they won't drop their leaves, or just be static from the shock of such a sudden change. It works for me.