Next does not support this feature by default, because it's primarily focused on visualization. However, there's a simple topology editor (follow the link: http://codepen.io/NEXTSUPPORT/full/mOoBqY/) that you can upgrade into the app you need. It certainly requires a module to convert the topology data into the format you use in your project; and it could be YAML too!
I absolutely agree that the Codepen example is too basic and you need something that is more comprehensive and user-friendly. As a matter of fact, our team is currently focused on a different project, but I believe we're back in summer
Your idea to create the topology editor is great. What's even better is that Next is open-source and everyone can contribute. It has everything to get started with your app (Next can manage DOM, track such events as click on a node, it can dynamically change the topology). So we encourage you and your team to benefit from it, and create the cool stuff with our framework! Basically, our goal is to provide you tools and documentation, while you can use all of it to create specific apps.