Interestingly, for this parallax 3D effect to work, the head tracking needs to basically move "backwards" from typical head tracking since it needs to keep the focal point the same, if I'm understanding correctly. Any time I've tried this out it's fun and would likely be most useful for something like a 3D painting you hang on your wall.

Related idea, but not the same, might be my iOS and Android app that uses your phone's AR for head tracking and then sends that data to your PC for smooth sim game head tracking. https://smoothtrack.app