One of my favorite moments of a show is when the Big Bad gets dragged off stage.
Not, however, because of "justice being done." In fact, my sympathies are usually with the Miss Hannigans and the Miss Minchins. (Note in passing that horrid Disney tradition of casting an older woman, usually unmarried, as the chief villain.)
Why it is my favorite moment, is that it marks the point at which I start turning off microphones that will never have to be turned on again. Most shows build to a peak, drawing together all the various plotlines, which means every character with a mic will have an important speaking line in the climactic scene.
Because the trick to a good mix isn't remembering which mics to turn on. It is knowing which mics you can turn off.
The fewer open mics, the less noise, the more clarity, the more room before feedback, and the less chance for accidents. So it is a wonderful feeling to be able to pull down a fader and know that you can finish mixing that evening's show without ever needing that particular fader up again. The scenes following the climax are a series of "good byes" to your open channels of wireless mic, as one character after another is removed from having anything further to say (or sing).
This is also true of ensembles. In a typical ensemble of twelve singers, two are in a quick-change and won't be singing, four are out of breath and aren't singing well, and two sing badly all the time anyhow.
The trick to getting a good ensemble sound is not in opening up every microphone that might have some lyrics coming into it. The trick is, instead, to find those few microphones which have a strong melodic or harmonic line in them. And you let the wash of natural sound (plus mic leakage) make those six open mics sound like they are carrying an ensemble of twenty.
It is a delicate balancing act between getting a "full" sound and leaving out those voices that are panting, off pitch, touching their microphone, or whatever. And between getting a clean sound, and having open mics for all those random lines of dialog that will inevitably be given to a character who never speaks or sings at any other point in the entire show.
And you risk, of course, making the call to cut the mic of an actor who is fumbling with their hat a split second before they blurt out the single line that is next in the post-Sondheim song in progress. Or being distracted trying to find that one actress who is completely off pitch and blowing the entrance of one of the stars.
And you'll never be able to explain why you missed the line. Because you can sort of push through a grudging understanding that the more open mics, the more chance of feedback. But you can not make directors and producers understand the mindset that looks not to which mics you can have up, but instead which mics you can safely turn off.