Preventing cross-scene references from the editor UI.
The default behaviour is to prevent cross-scene references from the UI.
Disabling preventCrossSceneReferences means that:
1) Dragging game objects to object fields for objects in other scenes will be allowed.
2) The Object Picker will show all game object of all open scenes (instead of only the game objects of the scene the object that is being edited belongs to).
3) No warnings will be logged when dragging objects from one scene to another scene which results in cross-scene references.