they will move faster in most cases, but you can lose stability and possibly do some damage. In the case of elastics, sometimes less is more and a good thing...
I have heard from many users that that they have cheated with more than 1 rubber band though... It's understandable as I know you want them off, but I would follow the directions of your ortho.
Braced Twice. Wear Your Retainers!
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