Is your feature request related to a problem? Please describe.
The current way build settings are implemented is quite unintuitive.
Describe the solution you'd like
Start sketching out an actual UI and workflow, improving the current experience. Consider using UIElements and check-box-based-foldouts to reduce the visual clutter and streamline creating a build setting for a single platform.
Tasklist
Sketch the new UI.
Research into what custom UI elements that needs to be created to help the new UI direction.
Look into whether tree view can be dragged-and-dropped hierarchically.
Describe alternatives you've considered
Consider also looking into the latest beta Editor XML to format the location of each button. If anything, the UI of the build setting inspector needs to get less cluttered, not more.