Sorry. I cannot force the developers to update UDL. There are plenty of issues requesting updates – and you can feel free to add more – but there seems to be a lack of interest in working on that component. (My thought has been for years now that the developer has an idea that he’ll write a new/better UDL system “some day”, but that he keeps getting distracted with general maintenance and other, easier-to-implement features.)
In theory, someone who had the skills could write a custom plugin-based lexer, similar to the GEDCOM Lexer available in Plugins Admin, which could handle your specific needs. Or, even better, someone could write a plugin-based lexer to basically replace the UDL system, but with more powerful syntax (full regex and full unicode support in every field).
I don’t have enough of the right skills, or the time, to devote to something that major, unfortunately.