Out-of-the-box Magik is powerful, but it is generic. Your network topology, your switching orders, and your connectivity rules are unique. Relying solely on standard methods forces your team to bend workflows to fit the software, rather than the other way around.
You're referring to "Custom Magik Programming" from a deep paper. Unfortunately, I don't have the specific paper you're referring to. However, I can try to provide some general information on the topic.
In the world of geospatial asset management (specifically within GE Smallworld), is the engine under the hood. Most users interact with the out-of-the-box (OOTB) functionality, running standard reports and editing geometry.