The artist nowadays releases a chapter each day, with exception of Tuesday (the day off) and Wednesday (when he works on the 18+ chapter). However, he got sick a while ago and went on a hiatus until 8th of March thus why there was a large gap.
If anything, I am afraid he will suffer a burnout.
This feels sudden. We were set up for a proper arc with that strict writer (which I feel was meant as a development arc for our boy), and now it's just ending? Something is off here...
The girls are added into the spin-off as they are introduced into the main story. At times, R-18 chapters were more frequent than the normal ones so that probably also slowed intros of other girls down (since the R-18 version is the one making author regular revenue, even during writing blocks...
Just like how nearly all Anime series are advertisements for Manga and Light Novels, some Manga are advertisements for Light Novels. If the Light Novel is popular enough, or the Manga adaptation is very popular, the Manga may go on until the end. Otherwise, it does its advertising and finishes...
One can be both smart and ignorant. The nobles are smart enough to orchestrate all this, but they most probably never saw the monsters or the tainted territories and could have assumed that it couldn't be that bad if it was never an issue before.
Multiple times, for several reasons, both in this version and the R-18 version I thought that Yuri felt the most like a "girlfriend" archetype for Sou. And seems like she will be the first on to dare trying to become his wife. Don't disappoint me, Yuri! Make this as funny as possible.
Finally, some manga touchess on the fact that reincarnators in Villainess Isekai basically kill the original (which is why I prefer time travel vilainess variant).
That granny looks like she had been an Otome Game protagonist herself long ago.
Anyway, Chibi finally has a friend. Even if that friend sees her as a dog.
Marie's later failures makes me think that in the main story, she collected the other four due to them being curious about who this girl whom the Prince likes is.
The Marie route didn't exist back then, it was written because of that poll. I assume the author expected blind hate (like what you can see of some posters here) but most were curious what the story would be like if Marie was the main girl.
Do not underestimate a writer's stubborness. The Manga publisher did so many screw-ups that the writer decided that enough is enough. Expecting that money could solve all problems might even be part of what led to this outcome.
Events are similar, but his behavior in those events isn't. In the Normal Route, characters actually make it clear several times that they hadn't had sex with Shou, and they fear that if they do he might hate them for it. By that same point, in the R-18 route they had sex with him many times. So...