The translator currently (when not setting one) falls back to the locale one level higher (eg en_JE to en). ICU contains data where the parent should be different (eg en_JE > en_GB > en_001 to en). Has using this data to produce a fall-back map been considered?

This relates to misd-service-development/phone-number-bundle#22, where I'd like to be able to use es_419 (Latin American Spanish) to save having to have separate translations for each of the 20 sub-locales (according to the ICU data).