Making QDGC is rather straightforward once the procedures have been set up. I used to do this using a combination of python and ArcPy libraries. In 2014 I programmed the procedures using FME and embedded python code.
Works like a charm.
The FME project is set up so that it calculates all countries in the world in one go. The output is still shapefiles. Next time I will probably provide them as national geodatabases. Mainly because QGIS now also supports this format.
The necessary scripting/code for generating the QDGC files is available on github: