Delay Inline JavaScript With W3 Total Cache

delay-inline-js.php

<?php
add_filter('w3tc_process_content', function( $content ) {
	preg_match_all( "/<script(?:[^>]*)>(?<content>[\s\S]*?)<\/script>/ims", $content, $matches, PREG_SET_ORDER );
	
	foreach ( $matches as $code ) {
		if ( strpos( $code['content'], 'jQuery(' ) === false ) {
			continue;
		}
		if ( strpos( $code['content'], 'DOMContentLoaded' ) !== false ) {
			continue;
		}
		if ( empty( $code['content'] ) ) {
			continue;
		}
		if ( preg_match( '/(application\/ld\+json)/i', $code[0] ) ) {
			continue;
		}

		$new_code = "<script>document.addEventListener('DOMContentLoaded', () => { " . $code['content'] . "});</script>";
		$content = str_replace( $code[0], $new_code, $content );
	}
	return $content;
}, PHP_INT_MAX);