I am wondering how one can use `fx:include` in conjunction with the JavaFX Scene Builder, therefore:

Imagine I have a `BorderPane` (file `borderpane.fxml`). In the center section I want to put a `Label` which shall however be defined in a separate FXML file, e.g. `label.fxml`.

**First problem of this**: As the `label.fxml` will be integrated into a container (the BorderPane) it doesn't need one itself. The SceneBuilder however only offers the option to create layouts being a container?

**Second problem**: I can create the `label.fxml` manually and then adapt `borderpane.fxml` manually to include the `label.fxml`. I then can load the borderpane.fxml file using SceneBuilder without any problems. However when I now change the text of the label and choose "Save", not the `label.fxml` is modified, but instead the `borderpane.fxml` is modified like this:

```
# borderpane.fxml  
<fx:include source="label.fxml" text="the new label text" />

```

The new label text should be written to `label.fxml`, not to `borderpane.fxml`, what is currently done. 

* Am I doing something wrong?
* Is SceneBuilder not intended to be used in conjunction with fx:include?
* I want separate Controllers for parts of my GUI, I think this is quite logically/normal, so this practical usage scenario is hopefully somehow supported by the SceneBuilder?