Agreed, I'll post my full thoughts tomorrow, but having just finished playing the update, yeah. This was very disappointing.
You're correct, there's nothing wrong with the actual storylines themselves, and there are some multi-girl options available. They're just so fucking short. Especially given the best note of comparison for these endings are the goodbye stories in S2, which were very well done imo, this was a massive let down.
Inceton really wanted to make sure this game was finished by the end of the year, and it shows, similar issues that lead to my major criticisms for their NTR release Thot on Trial back in August. They got delayed two weeks for the previous 0.9.0 update because they fired the head writer, and even this update got delayed a few days to make sure everything was ready. And it still isn't complete! Sophie's ending is not even in the game yet!
You can delay things! In fact, delaying the full release until early 2026 would've been the better move imo. Then you can really work each ending into a great finale. As it stands, the game didn't stick the landing imo. You get some nice little scenes, and then it just ends.
Also, no harem ending. Boo. Closest you can get is the foursome family ending (Megan/Jessica/Elizabeth), or the two throuple endings (Jessica/Chloe, and Megan/Zoe, and Jessica/Chloe is more a single scene in the otherwise Solo Jessica ending, and the Megan/Zoe ending is a massive letdown, not even a sex scene!) But as it stands? Half the endings lack any sort of sex at all, and they all kinda just end after a short montage.
Overall, a disappointing way to cap off this years long journey.