There is the following situation: in dialogues, one character always speaks, and the rest are silent, and can only approve or disapprove. Very rarely there are situations where the companion starts to say something, for example, in the case of the cultist Loviavar Astarion reacts very actively. But in most cases, companions are quiet.
I propose to do the same as in Dragon Age Origin - if there is any important dialogue, party members can turn in and express their opinion. Sometimes this can even lead to the appearance of new answer options in the dialogues, sometimes it will be just a neutral comment, or a comment that explains why the companion approves or disapproves. This will make them more alive.