The 804 has it's processor and memory power divided into different areas for differing functions compared to the keyboard; 7k has a sound dsp section, 804 has surround output for example, 7k has custom, 804 has progressive piano, they are different beasts for different riders

ASSUMING the 804 has no sound dsp section available within the menus (I can't check at the moment) which seems probable without a button on the panel, perhaps the save/load code was retained for simplicity and compatibility with the 7k but the sound dsp single should just have been blanked on the 804?