> In a blended wing body design you can have off-axis motion that can increase motion sickness
This sounds fixable in avionics and training. (Shallow, gradual banks.)
Note, too, that a larger lifting body needs to bank less to execute the same turn as a craft with more loading.
I learnt on mentour pilot (or maybe captains speaking?) that the airbus most of the time optimizes for comfort by having a constant g force as you ascend or descend or something like that. Unless you are high aoa. So there are systems that so this sort of passenger comfort thing for sure.
Sounds fixable by making the outer seats cheaper.
> Note, too, that a larger lifting body needs to bank less to execute the same turn as a craft with more loading.
This is not really helpful for passenger comfort. For a turn to be comfortable, you want the turn to be such that the effective force the passengers feel has no sideways (relative to the passengers) component, and the required roll angle is only a function of the velocity and turning radius. The aircraft design is irrelevant.
The Wikipedia article is mediocre: https://en.wikipedia.org/wiki/Coordinated_flight