I wrote that inlining your <svg>
icons makes for the best icon system. Scott Jehl wrote that just because you inline something doesn't mean you can't cache it. Let's see if Scott's idea can extend to SVG icons.
Here's the GitHub Repo.
This page benefits from the caching, where as this one cached the stuff.
You could definitely get fancier with this, with cookies or something to determine whether or not to display the inline SVG and cache it, or if you know they are cached and can show the <use>
stuff.