Theme settings other than "Max width"

I have tried Neptune 7.x-2.x-dev (2014-Apr-06) together with Zen 7.x-5.6, only to find out that it actually adds only one theme specific setting (the Max width). Unlike stated in the documentation, there are no other settings, such as Layout. You can only use this theme in the look & feel exactly how it is shipped, and it does not allow any customisation on colors, fonts or other visual elements. The use of a custom CSS file is also not officially supported. Unless more configuration abilities are added, I doubt if this theme can be considered useful for an end user.