About <script> tag

• <script> tags block rendering by default, so it was/still is a common practice to put them at the end of document, right before </body>. Exceptions are <script defer> and <script async>
• <script type="module"> is async by default, so <script type="module" async> is redundant.
• Injected scripts are async by default too.

<script>
  const scriptEl = document.createElement('script')
  scriptEl.src = '/yall.min.js'

  document.head.appendChild(scriptEl)
</script>