Why not external javascript?

Hello,
Really like this plugin and service, but I have doubts about the inline java-script it attaches to every single page. I am afraid it affects page speed load performance, as the code is not reused, when it could perfectly be hosted in a external javascript file.

For example, this is what I see attached in the source code of every single page I have:

<script src="https://cdn.onesignal.com/sdks/OneSignalSDK.js" async></script>
    <script>

      var OneSignal = OneSignal || [];

      OneSignal.push( function() {
        OneSignal.SERVICE_WORKER_UPDATER_PATH = "OneSignalSDKUpdaterWorker.js.php";
        OneSignal.SERVICE_WORKER_PATH = "OneSignalSDKWorker.js.php";
        OneSignal.SERVICE_WORKER_PARAM = { scope: '/' };

        OneSignal.setDefaultNotificationUrl("http://www.websitename.com");
        var oneSignal_options = {};

        oneSignal_options['wordpress'] = true;
oneSignal_options['appId'] = 'idnumber';
oneSignal_options['autoRegister'] = false;
oneSignal_options['welcomeNotification'] = { };
oneSignal_options['welcomeNotification']['title'] = "Website Name";
oneSignal_options['welcomeNotification']['message'] = "Gracias por suscribirte";
oneSignal_options['welcomeNotification']['url'] = "http://www.websitename.com";
oneSignal_options['subdomainName'] = "websitename";
oneSignal_options['safari_web_id'] = "web.onesignal.auto.number";
oneSignal_options['promptOptions'] = { };
oneSignal_options['promptOptions']['actionMessage'] = 'quiere notificarte cuando haga falta';
oneSignal_options['promptOptions']['exampleNotificationTitleDesktop'] = '¡Eres una mujer hermosa!';
oneSignal_options['promptOptions']['exampleNotificationMessageDesktop'] = 'Las notificaciones aparecerán así:';
oneSignal_options['promptOptions']['exampleNotificationTitleMobile'] = '¡Eres una mujer hermosa!';
oneSignal_options['promptOptions']['exampleNotificationMessageMobile'] = 'Las notificaciones aparecerán así:';
oneSignal_options['promptOptions']['exampleNotificationCaption'] = '(podrás borrarte cuando quieras)';
oneSignal_options['promptOptions']['acceptButtonText'] = 'CONTINUAR';
oneSignal_options['promptOptions']['cancelButtonText'] = 'NO GRACIAS';
oneSignal_options['promptOptions']['showCredit'] = false;
oneSignal_options['notifyButton'] = { };
oneSignal_options['notifyButton']['enable'] = true;
oneSignal_options['notifyButton']['position'] = 'bottom-right';
oneSignal_options['notifyButton']['theme'] = 'default';
oneSignal_options['notifyButton']['size'] = 'medium';
oneSignal_options['notifyButton']['prenotify'] = true;
oneSignal_options['notifyButton']['showCredit'] = false;
oneSignal_options['notifyButton']['text'] = {};
oneSignal_options['notifyButton']['text']['message.prenotify'] = 'Pulsa aquí para suscribirte a notificaciones';
oneSignal_options['notifyButton']['text']['tip.state.unsubscribed'] = 'Suscribirme a notificaciones';
oneSignal_options['notifyButton']['text']['tip.state.subscribed'] = 'Ahora ya estás suscrita';
oneSignal_options['notifyButton']['text']['tip.state.blocked'] = 'Has bloqueado las notificaciones';
oneSignal_options['notifyButton']['text']['message.action.subscribed'] = 'Gracias por suscribirte';
oneSignal_options['notifyButton']['text']['message.action.resubscribed'] = 'Ya estás suscrita a notificaciones';
oneSignal_options['notifyButton']['text']['message.action.unsubscribed'] = 'Ya no recibirás más notificaciones';
oneSignal_options['notifyButton']['text']['dialog.main.title'] = 'Administrar notificaciones del sitio';
oneSignal_options['notifyButton']['text']['dialog.main.button.subscribe'] = 'SUSCRIBIRME';
oneSignal_options['notifyButton']['text']['dialog.main.button.unsubscribe'] = 'BORRARME';
oneSignal_options['notifyButton']['text']['dialog.blocked.title'] = 'Bloquear notificaciones';
oneSignal_options['notifyButton']['text']['dialog.blocked.message'] = 'Sigue estas instrucciones para permitir notificaciones:';

        OneSignal.init(oneSignal_options);
      });

      function documentInitOneSignal() {
        var oneSignal_elements = document.getElementsByClassName("OneSignal-prompt");

        var oneSignalLinkClickHandler = function(event) { OneSignal.push(['registerForPushNotifications']); event.preventDefault(); };        for(var i = 0; i < oneSignal_elements.length; i++)
          oneSignal_elements[i].addEventListener('click', oneSignalLinkClickHandler, false);
      }

      if (document.readyState === 'complete') {
           documentInitOneSignal();
      }
      else {
           window.addEventListener("load", function(event){
               documentInitOneSignal();
          });
      }
    </script>

Any possibility upcoming plugin updates solve this soon? Thanks.

Placing JavaScripts in external files has some advantages:

1. It separates HTML and code
2. It makes HTML and JavaScript easier to read and maintain
3. Cached JavaScript files can speed up page loads

https://ww.wp.xz.cn/plugins/onesignal-free-web-push-notifications/