The problem in my opinion is the lack of the epilogue that they removed from the 6 months, if you see what the characters have been doing after the fact, you see that they are well and happy, you are satisfied and happy or sad about the decisions made. That doesn't happen here, you have nothing. Imagine for a moment that you had an epilogue where you see that yes, she is in hell, things are not perfect but she is happy and she is content, good with your Tav, that they have advanced and grown together. Isn't it so bad now? we need epilogues.
We also need to polish act three...
Minthara is still bugged, and even without that she and Karlach are both starved for content. I also see a lot of Halsin enjoyers asking for more fleshed-out romance options for him. Plenty of people are asking for cut camp banter to be added back as well. There's a lot Larian can work with for a definitive edition. I just wish they would tell us if they plan on working on any of those things at all. Maybe after their break, they will.
As for a Karlach epilogue, I wouldn't be satisfied with that. Even if she and the player are skipping through the molten fields of Avernus, it still doesn't change the fact that they didn't let us do "everything we could" to help her before that.
