Investigate server performance when Yoast SEO activated

[bobbingwide]

In my local development environment I've been developing the theme without WordPress SEO being activated.
I activated it for use by the sb-breadcrumbs-block and the server response has more than doubled. Why's this?

[bobbingwide]

One of the things I noticed when using Firefox is that when viewing the home page, there's a second request to load page/2
This is due to the <link rel="next" href="[https://s.b/bigram/page/2/](view-source:https://s.b/bigram/page/2/)" /> which Yoast SEO adds to the page during wp_head processing.

This prefetching is a feature of Firefox.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Link_prefetching_FAQ

The link can be filtered out by hooking into wpseo_next_rel_link.
But there's no context passed to the filter other than the link itself.
So implementing this hook might be an all or nothing thing.

The question is: Does Firefox remember what's been requested... so that if the user clicks on the page 2 link the request isn't performed again. How long before Firefox clears its cache of prefetched pages?