EmbedFallbackTranslationsPlugin doesn't reflect per-locale fallback configuration

[mingan]

We have I18n.fallbacks configured as

{"en"=>["en"],
"cs"=>["cs", "en"],
 "es"=>["es", "en"] ,
 "sk"=>["sk", "cs", "en"],
}

I.e. all locales use en as their fallback but sk uses cs first.

This works well on Ruby side but when running i18n export with EmbedFallbackTranslationsPlugin enabled, it automatically picks I18n.default_locale as the universal fallback. Is this intended behaviour?