I mean, the clothes in general are a lot and something a lot of VNs don't have to deal with. I think the closest is Extracurricular Activities and they all follow the same basic shape except for special occasions, where they typically have like a month for a single character route. And none of those are player chosen, so CGs don't need to consider what a user has chosen outside of the MC hair and skin color. Like, the amount of work you already do seems exhausting even before hearing that process. It makes sense for the story and getting players into the headspace of the master, as well as showing how much control they have over him superficially to imply just how much power they have in general, but it's definitely a lot. Seems like the new workflow should be better for not having to get creative to get the expressions you want, though. But yeah, no surprise it's in your top 3 after just how much you had to redo.
(As for shading, I used to digitally restore photographs from a few major companies archives at my old job. Since we would sell images as needed the idea was we'd fix up the image and then it would always be done. It meant less time to correct if I would see errors years later since we'd also do the often large prints ourselves so you could see every imperfection and digital mark. Eventually I had it down where I could over sharpen to adjust for the smudging with ink to look sharp and make it so all of my healing wasn't noticeable, but some of my earlier work looked awful and I'd sneak in reworking when I could. You just get so used to a process that when you find something better, if you're forced to keep seeing your previous work you can't help but want or need to redo it, especially if it's going to be mixed in with your more contemporary output. I am happy to not have to worry about that anymore lol. )