I love your work. These pase fee weeks, i just finished your now and then and i loved the story lone there, specially i had to play it 2 times because you can also make jukie and sydney come to you in the ending. Kinda surprised me too becuase i always thought mc will end up with carol as the official wife but turns out, if jukie and sydney follows you, mc will be ending up with Julie. Now i'm curious in this your new work, Toxicty, and i'm loving the story. Honestly, the story is too good so i wanna ask, when's the next update?
Looks like the public release for 0.10 is planned for September 21st. Have you checked Interim Domain ? It's also from them.
As for Now and Then's ending I don't think Julie and Sydney being there have a bearing on who ends up being the "main wife", there's a detailed walkthrough (the link is somewhere on their Patreon, for free) that likely explains how it works, just like there's one for this game and Interim Domain.
Edit: Thought you'd have to dig a bit to find the link but you can find everything on their "about" page on Patreon, links for the games and walkthroughs.
From what I know Now and Then endings with Julie and Hana as main romantic partners were added in directors cut and because of it there are determined mostly by one choice at specific moment beside overall good relations with them to have it. I know for sure that, if in the night after the main attack on Hana's house you chose "Stay in bed with Carol", then the ending will concentrate on a partner with the higher "Love points" excluding Hana or Julie.
Personally I really like, that ending with Julie was added, if you choose "Get up and check the staff quarters", because thought she was less shown than the others, she is my favourite. If you don't choose to visit main house or staff quarters after the battle, then probably the easiest is to get Carol's ending, because she has more opportunities to build close relation / get "Love points", but you can have with others, if you always prioritized spending time with them over Carol, or if many times you made wrong decisions in that relationship. Story of MC and Carol is the core of the plot, plus probably only with her it is unavoidable to start intimacy, so she being at the centre at the end is suitable and main plan of the creators. Yet, I appreciate that all relations have some depth and all potential partners have personality, also that even if you have chosen polyamorous path - the ending isn't the same, but defers depending on your choices.
What is different and in some ways make me uncertain about my choices in TOXICity compared to Now and Then, is that in this new game there is less openness about intimacy and unlike in previous one I feel bad as a cheater by having intercourses with all female characters (it is softened by some thoughts of MC, that he isn't sure about how any of the relationships are deep, or if any will continue) and I am not sure if symbiotic poly will be available at the end, or attempts of it will blow out in MC's face,