Yeah, that�s what I thought. I personally didn�t think it was exploitative, talking to her about it out of nowhere would only lessen her trust in you and you had no idea how she would react if you exposed the Prism to her. You did get the opportunity to "talk her down", but only after you both did the deed and after she opened up to you - which makes sense.
About the bit on character knowledge, it makes me wonder if that�s the reason we can save Minsc with the Prism and not Minthara. Because our characters were still unaware of what the Prism can do, depending on how you play it.
Except our characters can become aware of that fact throughout Act 1, especially if you postpone Goblin Camp stuff.
Kill duegar in Underdark, rescue True Soul Nere and you'll have the opportunity to explain to him the effects of the Prism and that cult are basically a front for mind flayers. Even the scene with dying True Soul next owlbear cave and tadpole extraction, Halsin's notes/tadpole sample and dissected Drow corpse in Grove are big "No-No" in regards that the cult can be trusted and that Absolute is a legitimate deity.
So if that stuff works on Minsc (with a bit of persuasion), Nere (passively the moment you encounter him), so it should work on Minthara.
