I think the most obviously jarring thing about the narrative is how decidedly laid back the origin characters are about their imminent and painful deaths, to then be replaced by a brain eating monster which they could reasonably anticipate occurring within a matter of days. Other than Laezel, they show very little concern over this obviously horrific prospect. She is the only one with any urgency. Wyll in particular is ridiculous, with his priority being on hunting Karlach, when he has no idea how long this might take and the real possibility ceremorphosis will occur before he ever finds her.
I get that they didn't necessarily want all party interactions to essentially be "Shit, shit, shit, we are about to die" until the first dream sequence, but if so, they might have chosen another plot device.
Still, I think its important to recognise its a game, not a novel. The plot needs to be an excuse for interesting scenarios for gameplay and interesting mechanical progression. Inevitably, some compromises are going to be made in terms of narrative flow. This is a particular issue if you don't want to put the player on railroads and allow them the ability to explore, do side content and advance the game at their own pace.
