Yep they're all cardboard cutouts in Act 3. I hear Jaheira and Minsc have more to say, maybe I'll try taking them with me some time. But I get so used to my main party I don't want to change them. Ascending Astarion kinda helps because his power trippy comments when he has them are so entertaining.

But even then I just can't bring myself to do the final battle and everything that leads to it because it's so boring compared to Act 1. And I still remember the last battle and ending in my first playthrough when my laptop was melting like Astarion's face and Karlach, half the textures refused to load, and letting Karlach live bugged me out of Astarion's epilogue. Good times.