At some point, the game is just going to have to develop a "Alexia is Wife" vs "Alexia isn't wife" variable. Then, most of the scenes with her can be designed around her being present or not present.
Once you have such a variable, then it's a lot easier to pick and choose what scenes Alexia is in, so that we have more room for divergences. Alexia x Andras can become a sub-variable of Not Wife, meaning we only have to account for it in not-wife allowing scenes.
By the same token, it would gate Alexia out of generic sex scenes, but allow wider divergences in sexual content.
But, such a thing is impossible in act 1, because we have too many random or one-off scenes featuring her, especially at her job events.
For the record: This isn't an ironclad plan or anything. It's merely the type of solution we're looking at to get around multi-state wankery.
I'm also primarily interested in the Alexia/Andras path, but I'm concerned: does this mean if you continued down the path Alexia would stop being Rowan's wife? I admit that the path would lose a lot of its interest for me there. I think it would turn Alexia into not much more than one of Andras' many sex slaves with nothing to make her stand out from the crowd.
I'm a bit disappointed that Alexia's path for both twins, but especially Andras, has been just that of sex slave. I saw someone earlier complain about this for Jazera but I think it's also true of the Andras path. Alexia just submits way too quickly. I liked the original opening more when she had sex with him out of being tricked and then hated him but was aroused by him nevertheless and was slowly being seduced by him. Once she had sex with him it's like there was a missing scene where she just agrees to become Andras's sex slave. Even at the end of the box event she's more demanding than a slave would be and the hint at the end that Andras still needs to do some work seducing her (but that she would be back) was titillating, but this jumped straight into Alexia being a sex slave. I wouldn't mind this as a path but I think a slower corruption of Alexia into cheating whore would be hot.
I also really enjoyed the hints from Rowan's perspective that something might be going on between his wife and Andras. That was half the appeal but those have petered off. The idea that Alexia could freely go to Andras's room if they're living apart and he can never visit her room or even her floor, so he would never know if she had done anything with Andras except by castle rumor, was erotic as hell. I'd love to see more of it or even a Rowan investigation subplot, which could lead in a number of directions.
I realize this is work and NTR isn't the most popular but this is one of the few games that really scratches that itch and I'd be one of the happy minority to see a more complex story in that area. I have my own tastes but having more options than just a choice between Andras or Jazera for NTR (like whether she becomes a sex slave or something more (or less!!)) would be really nice. Rowan's reaction would also be good, because NTR is about all the relationships and characters involved including the cuckolded husband. Being able to choose how Rowan reacts to this to help decide the eventual outcome would be nice.
Obviously that's really complicated since that's two to six Rowan NTR states combined with two to six Alexia/Andras states, just for an NTR subplot that a lot of people dislike, but I'd love to see it.
Perhaps it'd be possible to just track all of those with a combination of variables (e.g. a cuckold stat for Rowan to track how much he likes or hates it) and events and the final outcome are decided by the combination of stats. I don't know if that would save more work than having saved states that combine with each other. Broad categories (two or three different versions of a scene in terms of CGs but minor variation in dialogue and outcome) combined with said stats might also work. Just spitballing because I'd really like to see a more comprehensive NTR subplot than just whether Alexia becomes a sex slave to which twin.