The discover section now includes all of your custom metrics! When you are creating a dashboard, you can choose from your custom metrics too which saves a lot of time. Custom metrics also have their own detail page and a dedicated URL which you can use for sharing purposes. There are filters on the left-hand side to view all metrics, only default metrics and only custom metrics.
If you have any feedback or wish to learn more about the custom metric feature, please don't hesitate to contact us.