FYI: We in the Forum cannot change the codebase, and the Forum is not the official feature request location.
That said, even if you were to create a feature request in the official location (as described in the FAQ), I doubt it would be implemented. The UDL has not had any significant/meaningful changes in years. (The lack of UDL development is my biggest complaint about Notepad++, because there have been critical known issues, like not handling unicode characters, not allowing pattern matches rather than literals in the keywords and folding, and the other limitations in folding: I’m sure these limitations are chasing away many users, who would actually use Notepad++ if those were fixed/implemented. My long-term hope is that someone will take it upon themselves to write “UDL 3.0” as a plugin-lexer, and re-implement it from the ground up with the modern features, but that’s a huge ask, and something that I don’t yet have the skills or bandwidth to do [and aren’t likely to in the next few years])