I did some work with the translation config files in AC 5 or 6 or something, I don't remember. At that time XML hadn't come into fashion yet, so it was all text files. (In cases like this, I really can't see why you'd have to use XML when text files do fully well!).
In this case, it's not a matter of life and death to me, it's just that I want font mapping when dragging an external drawing instead of having to Open or Merge it to edit.
I still haven't had time to test this thoroughly. I doubt that a text file really becomes an xml-interpretable file by just changing the extension, but it's fully possible that the capability to interprete the text file remains within Archicad. I still regard it as a bug that the program ships with a Font Conversion file that is not selectable within the program because it's format is wrong.
I'd appreciate very much if you could send me a copy of the working Xreadconfig file that you have. I realize I won't be able to use it, but I may be able to understand its format. I'll PM you my email.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1