She is written as being mono for most of the game though, which you have said you agreed with before. They can't write a character as both monogamous and polyamorous, because they completely contradict one another, with two vastly different relationship views. A character can't be both at the same time and be expected to make sense.
So that's why they should have went all in on one direction, not this laughable attempt to appease both sides. It just doesn't work. Shadowheart is broken.
Yes and thats why I stated 2 my views on this situation and I like the one where it is wrong and is out of character. Yes she is mono and wants your Tav alone in act 1-2 and does 180 for some reason in act 3(reason is to let Halsin be horndog).