Eva should've never made both Ian and Lena playable at the same time and instead make you choose and make the other one an NPC who's decisions are influenced by the main character, similar how Jessica works in the game but more of it. Basically 1 main character and 1 main NPC.
She would still deliver on the original promise of "red string" characters tied together by fate, but it would make the game much more manageable. Two main characters creates so many moving elements in the story that it's honestly impressive how she still delivers updates instead of ending up in a mental asylum.