>What sequence of operations do I need to perform to achieve the desired end result? The "cad api" (literally an api in the case of code cad tools or the visual representation thereof in traditional mouse driven interfaces) does not work this way, and forces me to think about how to represent the finished shape not about how I'll actually make it.

Im not sure about CLI tools but I'd say that most parametric design (ie fusion, solidworks) software have robust DFM features as it is. Many softwares have a timeline that represents a series of steps taken to create your intended part. In fusion you can set up your project for Milling, sheet metal, or 3d printing and modify the tool paths and bends in suite.

Not sure what software you are using but I would step away from CLI of free tools if you are serious about parametric modeling