I already did this, But your method here is much more simplified , where as mine Needed so much more correction nodes and tweaking of pole vectors.
I will defiantly give this one a try.
Big Thanks
Indeed, it turned out to be incredibly simple once you figure out how the bones are rotated. Mind the fact that, at the moment, this is for a seated experience. If you move in RL, you will find yourself offset respect to your virtual body and will need to recenter (left grip button). A potential improvement for the next version.