Once you have calculated an .efractal file to 'completion' in Fred's Fractal Factory, the only way that you can modify the .efractal in the Factory is by increasing its max zoom depth. Generally after completing an .efractal file in the Factory, the only way that you interact and modify the .efractal file is by playing around in the Viewer and saving locales. But you can always reopen the .efractal file in the Factory to increase its zoom depth. The saved locales in the .efractal file will remain intact and still be available the next time that you open the .efractal file in the Viewer.