@bramus I dug into Safari's behavior a bit more (there's some pretty tricky code here). Your testcase is fairly unique in that your janky JS is "pure math". If you touch the DOM from that JS, Safari's behavior improves. https://t.co/wn4qHKPjyg
@bramus In the Safari the scroll is async, but painting tiles is blocked by the main thread so it scrolls blank areas into view. Not ideal, but the scroll itself is off the main thread.