Facet configurations are a powerful and useful piece of facet tooling most users, I think, are unaware of. It's buried and almost hidden on the first page of project creation and the description is unhelpful. We need to call this more to their attention. Also, on the facets page, the configuration description does not show at all. There also should be some text in a label or something expalining how to use the custom configuration options.
If you have ideas about how to better present or explain this to the user, feel free to contribute.
There is a suggestion for a configuration editor property page outlined in the wiki, please see for more details:
Bulk move of Faceted Project Framework bugs targeted to Future to the new project.