all this stuff in load_config() is stuff that could be moved out of this particular implementation of the BrrUi as the demo_ui_mode, and into a separate class that could be reimplemented easier for other users.
Not critical for now, but in terms of any future direction or conveying the idea.

I think for now, the key will be documenting how the parts of the UI, config, and functions, fit together so other people understand how they can use it, or modify it for their own uses.