I think minor rewriting in her conversation about Halsin proposal would do better honestly. To make her maybe less enthusiastic about it? And again just removing Halsin/SH banter or locking it behind double romance only(Alternatively they could rewrite it of course) and tweaking Drow convo(Remove disapproval at least, rewrite scene itself to include options to avoid certain writer's fetish. Or just remove halsin self-insert if not romanced completely) would do amazing already.
She is good as she is, just Halsin stuff needs to be fixed as he is the catalyst for all this.
So long as she accepts the Halsin proposal, I consider it out of character, no matter how unhappy she would be about it. Same way I consider Astarion's version out of character for him, and he doesn't show the same enthusiasm. The second either of them agrees regardless of the tone of their voice, I'd want to be able to ask "why Halsin and not the others though?" and that would need some serious explaining that will never happen.
And yes, the banter needs removal entirely regardless unless they rewrite her to be poly from the ground up (a lot of work right there since her act 3 romance arc will no longer fit her character), and then it should be locked behind romancing both.
