Yes, I would love to have something that would generate diagrams out of the code and hopefully could be 'live' so I could tweak it and for example provide initial value of some variable and observe where and how it changes things. I struggle every time when I am building something a bit more complex - visualisation like this would help me handle the mental model which is too big/complicated for my brain-RAM.
Including this alternative, built in AngularJS: http://sullerandras.github.io/SVG-Sequence-Diagram/