Some additions to the opening post:
- Companion quests for Halsin and Minthara in Act 3. For Halsin - Cloakwood is near the Baldur's Gate, so he could deal with some Shadow Druids plot in / near the city, especially if you revealed and stopped the plot in grove earlier and Shadow Druids try to get a revenge. For Minthara - since she opposes her clan after the battle with Absolute and before the epilogue, she could get a quest that would better explain her motives for this crusade (outside of just not worshiping Lolth anymore) - for example being ambushed in Baldur's Gate by Baenre assasins and investigating that further.
- Potential companion quest for Minsc as well and a bit of HP increase for Boo - he is too squishy against high-level enemies. Going for the eyes is a dangerous job.
- Possibility to cure non-ascended Astarion of vampirism (for example in Avernus / via God Gale's intervention / using Gale's scroll of True Resurrection etc).