Thanks for the response, it looks like there could be a dialogue between Gortash and Karlach that didn't trigger for me or Fasper.
I think I saw the scene in question going back and going to Gortash directly after dealing with Orin. I went through the coronation hall, but climbed the scaffolding behind it to get to Gortash.
You're right about the it feeling like Gortash's presence is a little sparse.
As for Volo, I don't think you can avoid a fight there, so it was probably a fun opportunity to have a Minsc moment.
