Sends the browser Speculation Rules (an HTTP header, so the strict CSP stays intact): the page under the pointer is prerendered, and the click feels instant. Pages that must not be prerendered — cart, checkout, account — are excluded. Off by default; one switch under Stores > Configuration > Zero.
The Speculation-Rules header and the rules the store serves.
What it does
Prerender on hover, in Chromium browsers; others ignore the header
