Gotta agree with that, I also don't think we'll get anything major before a potential definitive edition. For now I'd rather have them fix all the bugs that you already pointed out, especially with Minthara. With her and her giant mountain of bugs it feels like she'd need her own patch. WithHalsin, I don't even know what you'd do with him in Act 3 - he felt just so out of place there that I don't know what you could add. He does need something.
I am satisfied with the epilogues at this moment, and whilst I said "them announcing we could fix their engine" would be my favorite christmas present, this is close enough. I will take the optimism and run with it, for now at least.
As for the avernus ending hijacking the stories of other companions: I guess you can't have the cake and eat it, too, even though I get why it's bothering you. I feel more like there is a general problem with the endings, since the order of some of them is very strict.
Such as origin Astarion being unable to save Karlach, for example
I wish they'd polish that a little more, but sadly I doubt it.
The only thing I am certain of is that this wont be the last big patch we get.