Is there a way to control the mechanics of the animation? I poked around a bit and didn't see a way to configure what was sent down the arrows or how often - just some theming options.

For example, if you're visualizing a user flow, you might want rules about when new "objects" are sent down the pipe (example node rule: wait until received one item from each input), or how fast they travel, etc.

There will more a powerful controls for each node soon. For now there is a "Director mode" to control speed and traffic.