Maybe modern Xorg config files are not rocket science, but surely you remember the days of manually listing video modes, and trying endless combinations of video drivers. Hell I think you even needed to add special directives to get three button mice to work properly.
Fortunately those days are gone, but you definitely could debug xf86 config files.
Yes I do remember those days. And running XF86Configurator (or whatever the tool was) to try and guess a sensible setup. Guessing the modes for CRTs when it didn't work was a headache. Listening to your monitor going WHEEEEEEEEEEE and screaming in the wrong mode whilst hammering Ctrl-Alt-Backspace to exit before it blew up in your face.
But that article seems to be a strange mismash of odd name-dropping and a list of personal achievements.
It wasn't so much debugging as it was laying our your video card and monitor manual, listing the config file and making sure all the little numbers match up.
The coolest thing one could do with a legacy XF86 config and a CRT monitor was invent new "overclocked" video modes. I had one monitor that was rated for 1280x1024 running at 1600x600 to match another monitor for a Xinerama setup.
Fortunately those days are gone, but you definitely could debug xf86 config files.