In a plugin I wrote, I document some recommended settings for using Font Squirrel’s Webfont Generator. Currently, I’ve internationalized the strings, e.g.,
__( 'X-height Matching', 'text-domain' ), where
X-height Matching is actually a string found in the Generator.
The Webfont Generator is only in English so retrospectively I think it would be better to leave these strings untranslated since it could cause user confusion.
Seeking advice, especially from the translator community.