My point was to say that in the romanced path, you make your choices to benefit you & your play through. Though without the romance, he still wants the choice for himself. At this point, if you do not romance him, you have to "persuade him" to give up the ritual or you can embrace his choice. That would then only be you & your Tav's opinion related to your choices in the game. If you are just an ally with him, he wants the choice to make the decision himself, yet can't do without Tav's eyes. If you play the Origin story of Astarion, is the only time that the player, if they play true to the character can make the choice completely for him, but in the end, it is still just the player's opinion. All of his endings are related to the player behind the keyboard and their choices/head canon/opinion. It is a role playing game. Everyone will have differing opinions on how to proceed with that.
They just need to leave his character alone and allow the player to choose in the end. That is all I meant.
He never truly gets to make the choice by himself, it will always be how the person behind the keyboard wants to do it.