The panel for path component customization/settings suffers from several problems (APh & AD).
In the german UI the variable descriptions are partly not readable since cut off, either make the panel wider/bigger or the text for those descriptions smaller, so they are readable.
User variables can't be entered here (OSX El Capitan), those text fields are pretty unusable and do stop and block entry after just one character has been inserted.
I also pretty much doubt that own defined vars there would be usable and work at all. - Generally the whole panel design there is a nightmare and needs a huge rework. The online help related to these topics is also more than poor and a catastrophic!