What about adding internationalization support in the extension? Magic words does enable contributor to have localized aliases, so to my mind it would make sense that this extension also enable that.
Topic on Extension talk:ParserFunctions
Apparently they have this support, according to this comment
I'm rather unsure about it. I don't see anything related to localization in the repository expect for error messages. I'll ask on the ticket to be sure, thank you for the hint.