Yep, the preset are for the vanilla races. You'll see things like "caucasian001, caucasian0002" or something like that on the right pane. Unless you are modding your own race, you will have to alter the default presets. Don't worry, as long as the plugin is set as active, in other words the file to be modified, there's no real danger. You can always revert by simply replacing the file for the original or deleting it after deactivating it, as any simple mod. Unless you are doing a serious tinkering besides altering the default face features, because as you can see, the editor allows to modify all the content. I know this topic has been discussed in the forums before, maybe doing a search or reading the GECK wiki can give you more info.