Currently the label that is displayed is a database table name. The display is the same in the OPAC and Staff Interface. It would be nice to edit the facet label so the library can customize and add user friendly language. It would also allow the library to have nicer formatting, like consistent capitalization. Translations could be a factor, but could be added later. Right now, labels like 'ln' or 'su-geo' don't make much sense to the average user.
Facet labels can be edited in the Search Fields tab. However, I searched the manual and I couldn't find documentation for the Search Fields tab in Elastic Search Configuration. Changing the bug to needs documentation