I have an app extension with locales folder, can I allow merchant to update strings in locale files?

I want to give merchants control on what is shown. Similar how it is done with “Default theme content”, but for my app extension. And I want to utilize locale files for it, is it possible?

The reason for local files is that I want to use them for multi-language support.

I see an option to write those into metafields, but it feels incorrect as there is a locale system in place for this purpose.