Ok, so I read all the datamined lines more attentively. I was blined by an option to have actual ending with Halsin, now my mind is clear.
So... I don't like the ultimatum since Halsin acts wery weird, to say the least. People wanted to have Minthara without slaughter and I'm pretty sure they wanted to have both Halsin and her in party since we don't have a paladin companion, plus Minthara, as I know, an interesting character. In this case we see a clear example of OOC for Halsin - he is too capricious. And what about Tav who can be drow or half-drow? In this case a player would prefer only Minthara.
His "drow issue" and his abusive esperience... I don't know, looks clumsy,. If we already know how hates drows then why sleep with them? Feels like OOC again or problematic writing. This dialogue should be added BEFORE orgy.
About ending... Yes, I am happy, but Tav's line... what is this: "Don't be an ass"? What do you mean? Tav kind of forces him to be with them and we, players, wanted Halsin to say HE wants Tav to be with him. It sounds like:

- Hey, I have a new goal, but I will be happy to see you as soon as possible.
- Oh f**k you, I'm staying with you, no rejections since I won't accept them!
- Oh... ok.

Previous lines should be rewritten too, imho. Otherwise Tav looks kind of abusive and Halsin (if you look through all these datamined dialogues) looks like a spineless softy. Sorry, it may sound Harsh, but this is what it looks like to me now, when I can analyze what I see.
I don't know what else to add. One one hand Larian want to make changes for us but they are too weird and clumsy. If only Halsin wasn't turned into a mess from the very beginning... -_- I love him, but god damn it, why he suffers so much?