The multi-select feature can be used to size and scale titles in reference to each other.
To Enter multi-select mode, hold shift and click on multiple titles in the scene.
One title is the main, editable green title, while the other titles have gray bounding boxes in the edit preview.
You can scale and move the main title using its bounding box. To change the main title, click on the gray bounding box of another title.
Note: Scaling and positioning is only available in the Edit/Preview window, not in the Live Monitor Window.