I complitelly agree with you on the matter that Halsin has too little content. I wished that he'd have more dialogue and cut scenes and that the relationship would have a fuller story arc.

I don't agree about the polyamory, if I understood your point correctly. He doesn't force you to be with others, but he demands that if you are with others, they have to be alright with you also being with him or otherwise he won't do anything with you. He doesn't want to cheat others with you and that's why you have to ask your other partner first. I think that's great. He also tells that he isn't going to live in a monogamous relationship, even though at the time you are the only one he loves. I think that's fair, too. Honest. I don't think it makes his feelings towards Tav any less valid.