how to change the vertical distance between nodes

[graemep-nz]

Is it possible to change/ reduce the vertical distance between nodes?

Also in the online example
https://fluttertree.coldstone.fun/#/
there is a spinning mouse cursor.
Is that spinning because there is a real delay or is it just for demo purposes?

[xrr2016]

You could fork this repo and custom vertical distance between nodes;
Is real delay show get data from server, but in the example just await Future.delayed(const Duration(seconds: 1));