I have visual processing issues, and when pages contain sticky elements, when trying to scroll, the edge issues can trigger my migraines. It's worse when there's animation as the sticky element loads, when there's too much contrast, or when the sticky element encroaches on the center of the screen. (I use near-maximized windows, so that scrolling everywhere doesn't trigger my migraines.)
I currently have a Firefox add-on which can remove sticky elements after they load, but can't keep them from loading.
Is there a user style which can replace relative positioning with absolute positioning? So sticky headers and footers go to the top or bottom of the page, instead of the window? And side elements are the worst, if they can't stay put, can they go away?