The top List View displays the preset list, which is read-only and cannot be modified for the current version.
The bottom List View is the editable area. Clicking a preset will sync its content here, but any changes you make will only affect this local copy—not the original preset.
Presets are loaded once per Blender session, so reloading them manually isn't necessary. If you're seeing unexpected behavior, feel free to share more details—I'd be happy to help!
Fractal Family
Really cool. There appears to be a bug though where the presets don't always get reloaded on a new file, requiring enabling and disabling the add-on.