I’m a bit lost with this safari screenshot;

What I see;

Cache-Control is Must-Revalidate, No-cache, mage-age=0. I believe these things should tell the browser to check in with the server. However, you can see the Source memory cache, and no request was made.

I have, in index.html, a preload for this module, and without the module preload, the asset is reloaded as expected (from memory – the server responds with a 304).

Would this be expected? I expected the preload to check with the server – otherwise how can it know if its preload has gone stale?