speculative-loading-demo.php

<?php
/**
 * Plugin Name: Speculative Loading Eager Prerender
 * Description: Overrides WordPress speculative loading rules to use "eager" and "prerender" for better perceived performance.
 * Version: 1.0
 * Author: Your Name
 */

add_filter(
    'wp_speculation_rules_configuration',
    function ( $config ) {
        if ( is_array( $config ) ) {
            $config['mode']      = 'prerender';
            $config['eagerness'] = 'eager';
        }
        return $config;
    }
);