Had my first fall, 200+ hours in at Act 3.

My devotion paladin fell after using the runepowder bomb to destroy the foundry. I rescued a number of Gondians before and during, but I think a trio were unaccounted for, and the pier cleaners were missing post-explosion.

There seems to be some clever way to achieve the same result but I just went runepowder. Shrug. I guess it was fair enough.

The restore fee is now 1k gp, so that's better.

Regarding the Astarion plot:
My devotion paladin let hordes of vampires into the Underdark, no problem. Maybe specific dialogue choices matter, as my daughter and I hmm'd and harr'd over responses.