So I had seen some information on the sub in relation to having Utopia on the epilogue and wanted to test it out.

From what I saw on this sub, flirting with her in every given opportunity was a pre-requisite, but some also said that a Steam guide was saying you also need to be single for it to work - well, I tried it out while dating both Rex and Sym, and I still got her on my ending. You have to just not be in a monogamous relationship at the end. I also did not flirt in ALL opportunities, one of them I by accident gave a different answer when I did have a prompt to flirt, still worked out tho. So basically (afaik) what you need is:

• Explorer ending (just explore other areas as often as you can);
• Flirt with her as much as you can;
• Have high rebellion;
• Not be in a monogamous relationship.