Maybe this feature exist already but I didn't found it in the tutorial. As I used Blender 2D Animation Grease Pencil before, there was a really nice feature called "record animation".
This means to make any motion animation of some character by hand/mouse manually but automatically recording key-frames (every second).
For example I have a football. I click on the record button and make with my mouse some move. The software automatically record all (key)frames of the ball I am moving around every second/frame. Jumping the ball around in any direction with my mouse - it still record automatically all frames. This is not for complex motion/animation. But for moving things around this could be nice.
Another example would be moving around the eyes of some character.
But the feature of CTA5.01 with the lines and making the lines "round" is also good and easy. This feature is a little bit for more faster animation. It is only a suggestion, maybe this feature get some votes.