<flag name="lua">Include support for the Nmap Scripting Engine (NSE)</flag> It's probably a good idea to name the USE flag after the feature and not its implementation.
I needed to fix 9999 anyway, so I rewrote the ebuild real quick to handle simply being renamed for the next version bump and change lua to nse for 9999 only. I don't see a need to push this change back down into 6.47 at this time but it's entirely valid so let's use it moving forward.