Tog, thanks for the civil inquiry!
First, what causes the rider to follow the tangent of the curve? The reaction force of the snow. More pressure equals more reaction force, less pressure equals less reaction force. So if you flex and reduce some of the pressure, you will be at least temporarily reducing the reaction force. With less reaction force, the surface will be redirecting you upwards less then it would with more reaction force. So if you flex your legs lower down on the wall, reducing pressure and reducing the redirection...then your CoM is getting closer to the wall, its not running in tangent anymore. Its heading on a collision course for the wall. As you continue to move on more of a horizontal path that does not match the wall, the more acute the angle of the wall becomes compared to the direction of travel by the CoM. Eventually you will either be unable to flex your legs anymore and your body is going to compress against
I look at it like this as jamt mentioned in another thread. Hammer flies tangent to curve not directly out.
Reducing pressure is like lengthening the wire on the hammer ball. Or just lengthening your radius. I think. Pressure and standing height might complicate things beyond this?