P.S. Checking with a newer iPad, animation and motion sickness is more of an issue than brightness. Accessibility settings to "Reduce Motion" and "Prefer Cross-Fade Transitions" don't seem to reduce motion or stop page sliding.
I guess I'll need to figure out which pdf reader software would work, then which hardware would run it.
P.P.S. I've forked a separate thread for that topic:
https://www.mobileread.com/forums/sh...82#post4026882