<link rel="prefetch"> _can_ interfere with loading higher priority resources so we should delay adding them

[KyleAMathews]

From @yoavweiss in #12800 (comment)

I'd caution against heavily relying on prefetch's prioritization downgrade too much, as it doesn't always prevent contention with resources for the current page, especially if their discovery is delayed. It might be better to inject those prefetches only after you know that the current page is fully rendered and interactive.

We add prefetch elements here

gatsby/packages/gatsby/cache-dir/static-entry.js

Line 279 in c2b322a

// Add preload/prefetch <link>s for scripts.

We should instead insert a JSON blob into the HTML with these hrefs and add them as link elements once the page is rendered/interactive.

[thall1961]

Do you still need help with this issue?