I agree with literally everything else you said, but not this. Sleep gives time to process the thoughts and worries of the day, without being able to think of new ones.
Let me correct myself in that part you quoted then.
Sleep in not
necessary to maintain our facade around our parents and natsuki at night and in the mornings. Presence is, because barring some freaky 'watching you sleep' style parenting, knowing we're safe at home and expecting us to be asleep is all that is necessary for them to be at ease regarding us in this particular circumstance.
I was responding to very specific claims there in that quote you replied to. To answer more broadly, read below.
Well, if you start looking at things objectively, there is not a lot of things a magical girl needs. They don't need education, because they don't need a job, because they don't need money which, as Yumi demonstrates, are easy to find. They don't need family, or socializing, or food, or sleep.
The only thing they truly need are grief seeds. All the other needs have to be maintained artificially.
Distancing herself from people with a more regular schedule (since they can't keep up) and making further 'adjustments' easier.
I am afraid of cutting down restrictions placed on ourselves, because there really is no line that you could draw and say 'I'll stop here and go no farther'. Why would you?
Because the thread told her to, for one. Because the slippery slope is easily avoided if you see it coming and place limits ahead of time.
As for all the other 'artificial needs', doing those things are still necessary to maintain happiness, relationships, mental and emotional health. That's why she'd keep doing it even without forum intervention.
Yui wants to impress her parents, imagine how disappointed they'd be if she dropped out.
Yui wants to protect Natsuki, imagine how distraught she'd be if Yui went missing, how betrayed if Yui merely ignored her.
These are reasons to go to school, and talk to people, and have a life. Sleep isn't actually part of any of that. You're not pursuing any dreams but the literal ones when you're asleep. You're not deepening relationships or even selling a lie when you're asleep.
You're proposing that removing this one limit will lead to removing every possible limit when the answer is as simple as me telling you no.
It really is that simple, because VOTES. They really, really matter.
Sleep is one of the most important things in resetting emotional balance. I have serious doubts that mere rest will do it.
In regular humans who literally drop dead without sleep, yes. It has all sorts of benefits. In a being who doesn't need to sleep?
More importantly, if Yui's emotions seem to be running out of control, we vote to sleep. That'd count as a negative side effect that we keep mentioning, and we'd vote in ways that'd help remove or minimize negative consequences.
There are enough people who are against staying awake all night without evidence of any harm whatsoever that I believe it'll be rather easy to garner support for a vote to put Yui to sleep if it ever turns out she needs it.