Sometimes, HTTP request evolve and you have new field. When you do your http request "play" button, you can see the field but you cannot see it on your "detail component", so you cannot toogle the display. When you hit "reset" you loose all custom previex that you've done. Big lost of time.

One of possibility would be to let us add new field at the bottom of the detail component. If the field exist, with the exact same name, then you should be able to display the data.

This is the same working for Json type. When you select Json type, you can "add a new field", if the field exist, you will see it.