Dave Gailey

Preload resources that are likely to be discovered late in your page, but are otherwise important to fetch as early as possible. With scripts, preloading your key bundles is good as it separates fetching from execution in a way …

Don’t try preloading absolutely everything! Instead, select specific late discovered resources that you want to load earlier and use preload to tell the browser about them.

“All JavaScript! All hail JavaScript!”