It has now been merged to master. At the moment it’s behind a config flag because it’s not fully featured yet, so if you compile, run cmake first and enable KICAD_PCM. You will also see KICAD6_3RD_PARTY environment variable in the Configure Paths dialog, the packages which can now be tested will be installed there. The footprint library must be added to a library table manually. As was said, it’s not ready yet for full user experience.
Discussion should go to the dedicated thread.