I found it curious that it is a part that Larian mostly abandoned after D:OS1 - it was rudamentary, to be sure, but an ability to have a conversation between coop players and arguing how to complete a quest was an interesting fit when it comes for bringing singleplayers style questing into Coop. I don't remember having that in D:OS2 - perhaps there are some instances, like letting your coop player ascend. but In my shortish experience I didn't run into those.
I can't say, I would want Larian to pay even more attention to Coop then they already are for Baldur's Gate3 specifically, but otherwise, I think I would be interested in seeing them double down on coop, rather then trying this hybrid-thingy they started with D:OS2. After all, coop has been the feature that's been making their games stand out from the pack.