Choosing the right Raspberry Pi case can be challenging. There are many styles to chose from, but which one is right for your project. Many do not have room for adding an expansion HAT, and most have few openings for wires, camera cables, or sensors. I myself own about 6 different cases I purchased online. Each was either attractive or had a useful feature for expansion, but none were right for every project. After a couple of years of Raspberry Pi projects I finally decided to utilize Fusion360 to design a case system that would have some standardized connections for add-on components that could be mixed and matched into many configurations. There will be many vertically stack-able units with a dovetail joint each end for extending horizontally. Once all the basic case parts were created like a basic Raspberry Pi Holder case, a lid, a battery case, new components were easily created by cloning those designs into new ones and different features were added.
After designing the basic Rpi case and a basic lid with no openings, a 10mm tall lid with custom openings for covering an AdaFruit Motor Hat was created. After that the ideas just snowballed into so many ideas for "Nice To Have" components. After a month of ideas and Fusion360 edits, there are now enough components to create a wildlife cam or a rover control. Below are some of the new components for a 4G connected live wildlife watching cam.