We just had the situation that we could not complete a stage because for some reason an enemy was somehow hidden and we could not kill it. In this instance it would have been nice to be able to push the stage reset button. Of course I suggest to put up a timer between pressing the stage reset button and the actual reset in order to prevent people pressing it when they are about to lose a fight. Or implement any other condition that prevents abusing this button.
Also this button should disappear once the last enemy is destroyed and before the verse selection begins so that people won't use it to get better verses (although I don't see much value in that).
But maybe there are other ideas to avoid this impossibility to complete a stage to happen.