I love Karlach as a character. (I'm not sure if we still have to use spoiler tags after 100+ pages, but here goes.)

I am glad that the Avernus option was added for Karlach, so that she at least has a chance now. I feel like the fact that she is originally adamant about not going back, but learns to reconsider it once she has true friends who'd be willing to back with her, is a great development. I do think that adding more options for her would be appropriate. If/when a significant content expansion might happen for the game broadly, I think it would be hard to justify not expanding Karlach's content too. In the meantime, it might be appropriate to get to talk to the Gondians about her situation, even if it turns out that there isn't time for them to fix her before things reach a head.