Thanks for your feedback!
Technically, it would only take two lines of code, but it would hurt the user experience. For example, most YouTubers in whatever language you’re targeting have at least written their channel names in Latin script, and if the English language filter is enabled, they would get filtered out too, which is naturally not what the user wants. Adding English and other Latin-script languages may be possible in the future, after the other extension features are completed and after extensive testing, as an extra feature, but I can’t promise that.