[NTG-context] MetaFun keywords extracted by mtxrun --script interface

I am updating Vim syntax coloring for Metapost/MetaFun, which is now based on the files that are automatically generated with mtxrun --script interface --vim To test the results, I am opening ConTeXt's own MetaPost files in the editor and check how they look. It seems that the output of the above command is missing several "keywords". For instance: beginglyph, endglyph, anglestriped, numberstriped, roundedsquarexy, starring, dashing, pathpoint, primitive, immutable, etc. Is it because MetaFun keywords are picked up manually? Nicola