Hard agree on this, they at least should've added option in some conversation early in act 3(around her skinny dip scene timing) where you could say that you prefer full mono or something. That would place flag that you decided to go full mono and all that "interesting" things with Halsin wouldnt happen, also Mizora/Haarlep/Emperor flings would result in her massive disapproval if you ve chosen to go mono. At least thats how I d imagine this.
