Now that they added such a nice epilogue party, they should also change the ending itself. If they insist so much on having Astarion burn in the sun, I would like to see a short scene where they all go look for him, find him and then go into the tavern and toast together and have that be the last shot before the private conversation with our LI.
It would help, in my opinion, if they took the whole scene and not only a portion of it seriously. I mean, what happens is, that right when they are feeling good about themselves and want to celebrate, two horrible things happen almost at the same time, both Astarion and Karlach go up in Flames. If some of those who aren't necessary for Karlach's scene went after Astarion instead, that would help a lot - maybe some of the spellcasters who could actually do something useful or heal him.
(Though my headcanon remains, that the remaining gang meets at Nine-Fingers Bar to celebrate/mourn that not all their friends can be around.)