The current model of some story progression, and some sex stuff is actually ideal. And I don't care that the stats have been abandoned. They don't fit the way the game is being presented anymore.
What does feel lacking, and would be very nice to get a bit of in each release, is some character progression. Not every character needs to be in bashful love with MC, and thus not every character needs the same kind of development, personality, or followup.
I would personally prefer more time spent on the personalities of Zero, Lyra, Scarlet and Sarah. Daisy was also amazing during her character arc. Nadia is currently pretty average but her model is amazing and she could do a lot of different things, personality wise.
As far as kinky stuff goes, pet play, collars, room assignments, ie bathing assistant, dungeon assistant, farm assistant, military postings, just like the work assignments that existed at the beginning of the game. But because you're relationship is already developed the interactions are more playful, and they're wearing less. (or more)