The dialogue with Barcus after rescuing him is also missing more options, I think. There should definitely be another dialogue option aside from saying that he is far away from the Underdark or leaving. Barcus lived in Baldur's Gate for some years, and presumabely, he is not the only Deep Gnome who does not live in the Underdark, so it is likely that our Tav has met Deep Gnomes on the surface before or has at least heard about them.
If I don't want to play my Tav as very ignorant, I have to choose "Leave", but then I will not learn that Barcus is on his way to the Underdark to search for a friend who had gone missing.
An additional dialogue option where our Tav could ask where Barcus is going now could also lead to this dialogue part. New dialogue recording wouldn' t even be necessary.
