Custom Element pattern with i18n

pattern.html

<my-element>
  <!--
    provided content kept active (not inert)
    .screenreader-only added in Custom Element lifecycle
  -->
  <select class="screenreader-only">
    <option></option>
  </select>

  <template class="intl-messages">
    <intl-message msg-id="hello" lang="en-US">Hello, { name }!</intl-message>
    <intl-message msg-id="hello" lang="es">Hola, { name }!</intl-message>
  </template>
  
  <!-- generated in Custom Element lifecycle; has attached shadow root; possibly hidden from SR -->
  <div aria-hidden="true"></div>
</my-element>