You can add more captions in a frame with the Expert Plan and time it individually to show them in different positions in the same frame.
The new caption types that you unlock are called Bumper or Lower Third - find them in the more options tab.
A Bumper stays on for the entire duration of the scene. You will need to add a Bumper to every scene if you want it to remain for the entire video.
A Lower Third comes and goes independent of the captions. You can use Delay in Timings to show multiple captions in the same frame simultaneously.
Note: Lower thirds should NOT be the last caption in a scene. You can reorder the scenes to ensure that the last caption in every scene is always "CAPTION".
A short look at Bumpers and Lower Thirds being put to work: