I think the issue is that Nyx added a lot back to the beginning of the game after the first couple releases and most didnt start it over again to see it, I had to start over and there is a bunch more backstory and interactions early in the game to make up for some of that feeling. I felt the same, too much too soon, after this initially release but now its a lot better. Might wanna start over and see if you feel the same if you havent done so.
I hadn't played it until recently, so my only experience is with the current build. I still think it's pretty good, as I said, but from your description, in some ways the flashbacks made it worse (but I'm not sure which flashbacks may be new, so I could be mistaking your meaning here). The position of the whole segment where we first meet the stepsisters is just really jarring. This would work much better if it was set chronologically. I get that some of the flashbacks are there to deliberately hide things from the player (not my personal preference and I don't think it particularly adds much as a narrative choice in this case) but that one is particularly egregious. Mostly because it is so long, and is just dropped in the middle of getting to know the characters at the new school etc. Apart from it's position I really liked the section, apart from how abruptly it ended after making the choice, that was weak and rushed.
The position of the step family section within the subjective timeline also makes the first part, on the plane feel really dodgy in hindsight, being as it is chronologically immediately after the step family segment. Either that or the MC really is just a huge horndog that the author is weirdly desperately trying to make appear sympathetic and not a huge douche.
This is what I meant in my original post, it just feels really busy, like the author is really trying too hard to push the whole small world / everything is connected angle, to the point of absurdity. But at the same time trying to make the characters realistic. Well, apart from the MC, who is apparently literally sex on legs.
But despite that, it is fun.