FrankenPHP natively supports the 103 Early Hints status code. Using Early Hints can improve the load of your web pages by 30%.
<?php
header('Link: </style.css>; rel=preload; as=style');
headers_send(103);
// your slow algorithms and SQL queries 🤪
echo <<<'HTML'
<!DOCTYPE html>
<title>Hello FrankenPHP</title>
<link rel="stylesheet" href="style.css">
HTML;Early Hints are supported by the normal and the worker mode.