I need access to some private headers from the multimedia and core modules.  To do so, I need to add the following to my qmake .pro file.

QT       += core-private multimedia-private gui widgets printsupport opengl

and the following in my CPP file  (just one example for now)

#include <private/qaudiosystem_p.h>

In 3.1.0 Rev 2 - the correct include path was added to the VS 2022 project.  In the latest versions the path to the private modules parent folder is missing.