TIL: Chrome DevTools Layers tab, accessible by going to to the three-dot menu > More Tools > Layers, which allows you to see things rendered outside of the browser viewing area (among many other things I'm sure).
If you have something that "unmounts" things as they scroll off the screen ("virtualized rendering" as the article calls it, a common feature for data grids), this is great tool for verifying that behavior.
I really should look into virtualized rendering; turns out I've got some really long lists that are mostly hidden (overflow: hidden I think) that shouldn't be rendered.
If you have something that "unmounts" things as they scroll off the screen ("virtualized rendering" as the article calls it, a common feature for data grids), this is great tool for verifying that behavior.