How to get to the Editor to display a child's World Position?

You could make a custom editor that displays the world position. Here's a simplified example. You would probably want to do something a little more complicated since this overrides the default view.

//WorldPosViewer.js
@CustomEditor(Transform)
class WorldPosViewer extends Editor {
    function OnInspectorGUI() {

        EditorGUILayout.BeginHorizontal ();
        target.position = EditorGUILayout.Vector3Field("World Pos", target.position);
        //this will display the target's world pos.
        EditorGUILayout.EndHorizontal ();

    }
}

This code is fairly simple. It just displays a Vector3 field in the Transform Component instead of the standard local coordinates. The problem I spoke of earlier is that you need to add back in the functionality for viewing the rotation and other properties since this overrides them.

You could also inspect a different component that you know your object will have then indirectly access its transform.

`target.transform.position = EditorGUILayout.Vector3Field();`