The provided example showcases a simple plugin known as rete-readonly-plugin. When activated, this plugin prevents the addition of nodes and connections to the editor's core, as well as the translation of nodes within the area.
On the other hand, the plugin intentionally lacks various customization options to keep it simple, allowing you to explore its source code and create your own solutions tailored to your specific use case (e.g. restricting the addition of specific node types only).