"At Cloudflare, we use Astro, too — for our developer docs, website, landing pages, and more"

[1] https://blog.cloudflare.com/astro-joins-cloudflare/

I didn't heard about this thing until today, are you sure that it is already implemented in all major browsers? I have found this source [1] but for what I can tell, at the moment this feature is behind a flag in chromium and firefox (maybe it is already implemented in Safari).

[1] https://www.jefftk.com/p/shared-cache-is-going-away

https://bugzilla.mozilla.org/show_bug.cgi?id=1536058

https://bugs.webkit.org/show_bug.cgi?id=110269