Wow, what a lot of info!!
What I can gather from all of this is that all motion in a saeway will affect all of us in a different way and to different degrees.
Multi vs Mono; on deck
or below; medicated or not, eaten or not, all make for a huge number of variables that make the diagnosis and treatment an inexact science.
I am lucky in that I have never had really bad seasickness. Maybe because as a younger person I used to go out of my way to catch a ride on the Manly Ferry
(Sydney Harbour) on really rough days.