I mostly read just the story updates so there is always a chance I missed something but I do remember the QM shooting down @Sentient Tree's battle optimizations for Walpurgisnacht - which, supposedly, is the endgame of the quest. And even though a lot of the conflict does in fact revolve around hostilities, combat is pretty much always guaranteed to go in the player character's favor because her team is just ridiculously OP. The QM asserts that combat power isn't the driving force in the quest but when a lot of the angst is whether the characters will survive Walpurgisnacht this time around rings somewhat hollow.
But the worst part is that things the players post outside of votes actually makes it into the player character's head. Why is this bad? Maybe pointing out that I only found about this after reading the Staff Posts moderating players blaming each other for putting the wrong thoughts into the PCs head even though those happened outside of votes would help show why.
*PMAS*
Yeah, I'm taking a break from reading it after that. I think part of the problem there was that the QM is much more subtle about things than they think they are. As you said, it's not obvious at all from just reading that combat power isn't a driving force of the quest, but when I suggested that they be more obvious about for the more casual readers the QM said that they believed they were extremely obvious about it and cited the (admittedly numerous) times they implied that social is the only important thing. The problem is that while the regular posters all delve super deep into the hidden meanings of every word in the quest and every spin off of the source material, casual readers like me generally can't spend the time to do that, and aren't following the discussion where everything is analyzed to that degree. So casual readers miss the hints about social being all-important because every hint is buried under about 2-3 layers of subtlety. Even when the QM basically came out and said it to me, they said it subtly enough that I wasn't completely sure that I was interpreting it correctly until he confirmed. Until they said how blatant they thought they were being, I was half convinced that I was overstating things and would get corrected.
PMAS is kind of the exact opposite of Clear Communication Technique. That's a valid way to run a quest and obviously interesting to the right people, but it does not make it easy for people like me to figure out what is and is not a good thing to talk about.
I hadn't actually thought much about how the thread directly affects Sabrina's thoughts, but that would certainly explain some of the regular posters' attitudes towards casual posters and certain ideas.
As far as write ins go, I would suggest that it's a matter of how much preparation the QMs want to do and what kind. The MfD QMs have created a large world with many different things going on in it, so if we go way off the rails they still have some idea of what is happening wherever we go. A lot of QMs probably focus more on the events/locations directly in contact with the player character, which allows them to make a detailed story for less effort. They don't have to think about how anything effects the wider world, because the wider world isn't particularly fleshed out except where they expect the players to interact with it. This means however that if the players go off the rails, the QM doesn't have a clue what should happen.
For example, in a quest where the players are facing an important yakuza boss and need to get a rare scroll from him. They are given the option to bribe him or try and steal the scroll without him knowing. The QM then wants this boss to be a major player for the next arc in the quest, where he will hire the players to go on some quest in a foreign land that the QM spent a lot of time fleshing out. In a hypothetical situation where the players get a write in, if they instead kill the boss, grab the scroll, and escape after getting their face seen, the QM now has no clue what happens next. The entire next arc is now gone because there's no one to hire the PC for the quest, and they are now a wanted criminal so no one will hire them anyway. This wastes large amounts of time for the QM and forces them to spend more time to try and figure out what happens next.
In contrast, MfD is (I assume) somewhat more fleshed out as a world. The QMs put in tons of effort already to decide that the yakuza boss was an important henchman for the Village Hidden in the Beef, and so they know that now Beef ninja will be coming after the PC to kill them. This means that they know that the next arc now suddenly becomes a survival arc where the PC needs to escape their pursuers. Much work is wasted, but at least the quest still has a direction to go in.
That's my interpretation, anyway.