Well, an easy way, if nothing else works, is to cut down on the amount of stats. I’m not sure how the progression you have in mind looks but it could be an option.
The way progression in Harem Hotel works comes to mind here, where characters mostly have one stat (affection OR obedience, depending on the type of relationship) that governs unlocking of scenes but where this stat is checked is for events that advance a “relationship level” and that is what actually unlocks things. (i.e: event X requires 20 affection and will unlock BJs, etc..).
Given the way the game’s main structure is taking shape, what I would consider, though, is different tracks.
Obedience is related to rituals and scenes in the dungeon. Could also work as requirement for certain work tasks. From a fluff sort of perspective, I agree with kinkofnowhere in it governing general submissiveness, but an easier way to control this than H-scene variants would be through their responses and prompts for regular tasks, perhaps their efficiency and learning cap as well since right now the maxed out test implies they ignore your commands.
Love could, then, govern progression through their romance questlines which the demo already alludes to. It’s looking like those will be different scenes so they could remain mostly separate. Having a divide between these would also open up the possibility for future divergence in terms of ending if you end up going towards that direction (i.e: did you have a favourite throughout the game? Did you make any fall in love or were you just a self-serving master? etc…). But even if you don’t (because that could be a lot more work depending on how deep this rabbit hole you decide to go) this would already make it so that it gates different content and, as such, as a player, feels like a separate goal in and of itself.
This approach would integrate well with the ruling decision system, since it would be easy (one would hope) to have some of the afternoon events where you could have “option that sucks, option for a maid that’s obedient, option for a maid that’s in love” for some events, which would make different stats feel meaningful.
Lust maybe the trickiest one here. If you change how it works maybe it can eventually replace the cooldown timer for the ritual acts or at least influence it? That could be a bigger rework tho. Again, kink’s ideas here are a good start, I think. Another thing more or less along those lines would be relaxing obedience requirements for certain acts (assuming the changes I pondered about here). Or the maid’s lust could be correlated to the effectiveness of the ritual? Right now the whole portal power and ritual system is very early days and the bit that explains that isn’t in the game yet (or if it did make it in I accidentally skipped over it, oopsie) so maybe this could be an option. Things like Beth and Oinky’s events are also just a prime candidate to being governed by lust but I do think that ideally Lust would also have some mechanical effect in the game.
Finally, for the grindyness I think a large part of it is that the player is quite limited. You have 4 characters to work with but your progression avenues are super restricted. You can increase one stat for one of those characters each day, and it doesn’t even increase much. Afternoon entirely dependant on event queue and evening, if you don’t have to do the ritual (which right now you can’t even do often enough to keep the portal in check). Maybe a quick way to alleviate it would be to have day activities provide stats? If a maid cooks, have her get +1 cooking, maybe +2 if the kitchen is upgraded. If a maid is set to clean, maybe that gives her some extra obedience (they seem to constantly remark how that’s the most boring job) etc… Signposting these to the player will also be important, maybe an “end of day” report on the corner with these changes, just to help sell the idea that “don’t worry, you’re advancing here”
Anyway, that’s lot of rambling suggestions. During early days like this, it’s hard to see clearly the details of things and also to make sure you don’t immediately overscope everything so a challenging stage for sure. Hope all of this gives you some food for thought in how you eventually decide to tweak things.