The fundamental problem this game with narrative is that Larian think the player will:
A - do what they think with Illithid power, and have tied half the story to that assumption - despite also telling players NEVER USE THOSE POWERS
B - gives a crap about their origin characters, rather than treating them as maybe companions
I am depressingly convinced that a player who never uses illithid powers and doesn't use certain origin companions will be missing heaps of content when they play the game.
Creating a game on the assumption that players will either play a certain way, or that they will re-play the game like 10 times to get all the companion exclusive content, is really poor, and incredibly inefficient, design.
They would have been finished making the game already if they stuck to a BG1/BG2 narrative and plot design, and had heaps of room left over for the type of suggestions for content - linked to the PC - like those put forward in this thread.
