[danabramov]

That's also not true? I'm navigating between pages, and it does get served from cache for all subsequent navigations.

The only case when this code gets loaded is the literally the first cold load of the entire site — and it's only used for powering live editable interactive sandboxes (surely you'd expect a in-browser development environment to require some client-side code). It doesn't block the initial rendering of the page.

What is the problem?