The Quen sign is extremely useful to protect yourself against enemy attacks. The base version also doesn't last long, but if you upgrade Quen itself or increase your sign intensity Quen can last for a pretty long while. The disadvantage being that you don't regenerate vigor while Quen is active.
After battle, you don't want to enter the next one with an almost depleted Quen and an empty vigor bar, caused by the still active Quen which prevented vigor regeneration. It would be quite convenient to just disable Quen after battle. Is there any quick way to do that?