[Perseids]

This feature actually existed (see https://en.wikipedia.org/wiki/HTTP/2_Server_Push ) but was deemed a failure unfortunately (see https://developer.chrome.com/blog/removing-push )

[eru]

Thanks for the links! Yes, my comment was based of a vague recollection of this kind of thing.

I'll read up on the '103 early hints' and 'preload' and 'preconnect' which might be close in enough practice.