I don't expect much from Ellie and Dylan relationship, Ellie really seems to hate him and Dylan just don't know what to do with her even if he is good to her or talks to her civil, but maybe with time instead of hating each other more, they could at least try to get along or be less in each other's way instead of the contrary because the "sibling rivalry" thing can possibly get either, boring, predictable, unrealistic or simply annoying, they're siblings they can get along without having to engage in anything intimate at all or ever since Dylan main focus and priority is Sophia but at least to show to each other that he has a sister and she has a brother to count on when or if shit gets crazier for one of them.
I like the idea of him saving her or do something good for her in contrast from her prank (which he should, in the end, be very grateful for it), that would show her that there's no ill will and they can get along, maybe to to point that she can eventually understand Sophia and Dylan intimacy if they ever get caught by her and in a way she can help them with Liam from ever find out, and Dylan could do the same for her in some way. It really doesn't need to give too much emphasis to them, to be honest, but I guess it could be better to have an extra ally in a sister or a brother than having an extra thing to worry about.
It could probably work in both paths for each player's playthroughs, Sophia and Ellie (if that's a path because I don't know) and Sophia & Dylan which in my case is my main path.
