I wonder if the nausea issue will resolve itself over time. I think the unknown creates a lot of the problem, the first time I rode Everest I nearly hurled on the backwards part because I didn’t know what was coming, now that I’ve ridden a few times I can predict what direction we’re turning ahead of time (despite going backwards) so I don’t get nauseous anymore.
The same was true on FOP, I nearly fell down after my first ride because I had such bad vertigo, now I can ride it with no problems.
They didn’t physically alter either ride but just knowing what’s coming allows my body and mind to handle the motion better. The people who can’t handle the motion will also quickly learn to avoid it, problem solved.