Looks like the Pi 1, 2, and Zero are 32-bit (and probably other old or low spec SBCs). I’m also not sure if Firefox is distinguishing between 32-bit ARM and 32-bit x86.

That paper isn’t quite as compelling as I’d hoped it would be for your conclusions. It’s good research, but I’d really like to see a larger sample size, differentiation as to whether people are choked to the point of passing out, and more cognitive tests (because this paper didn’t see any decrease in ability).