In Logic X (10.10.3) the JUCE demo plugin has one Factory Preset in Logic's plugin presets menu called "Pres 0: Default".
However, nothing happens upon choosing this preset.
The existence of this "Ghost preset" is related to this issue: http://www.juce.com/forum/topic/problems-soundforge-and-vegas
The clean solution imho is for the plugin to report zero factory presets and have the work-around for SoundForge/Vegas be in the VST wrapper instead of in each individual plugin and not negatively affect other formats.
Cheers, Yair