Thank you for contacting us. Currently with the latest update, you will be able to configure your device as a test device and load test ads with your Ad Unit ID. This way you will be able to test your production ads on your test device. Please refer to
this guide for more information. That said, on beta testing, you can enable live ads and distribute them but I would still recommend you to enable test ads until you completely go live with the application. Test ads are recommended when the app itself is under development. If you have any further concerns regarding this, I'd suggest that you contact the
AdMob Product Support Team.