tell me how it makes sense that she will accept poly/open with Halsin but not with the characters that she was way more attracted to.
It requires so much suspension of belief that it's just incredibly bad, inconsistent writing. That's the whole problem. And yes, Halsin's characterization in act 3 is incredibly bad right now. That's why the Halsin thread is even longer than this one.
I generally think that's something that would be adjusted about the interactions if they did fix Halsin's Act 3 characterization so that's just me not thinking it needed to be specified separately.