Modify the Flarum UI

custom-header.html

<script type="text/javascript">

var thisHackInterval = setInterval(function(){

  // Check if app is available yet
  if (typeof(app) == "object")
  {
    // Set app routes to whatever I need
    // This will repaint the DOM automatically
    app.routes.settings.path = "https://my.laravel.site/preferences";

    // Remove navigation elements I don't want
    document.querySelector("li.item-logOut").remove();
    document.querySelector("li.Dropdown-separator").remove();

    clearInterval(thisHackInterval);
  }

}, 500);

</script>