Show us how it reduces jitter? Show us it lower distortion, show us it lowers channel imbalance?
You're still not reading :-(
They never claimed it
reduces jitter or distortion or channel imbalance. Rather, the effects of jitter, distortion and dynamic channel imbalance are mitigated by rearranging them to strongly correlate for the usually dominant mono(center) content which makes it less irritating.
This is a psychoacoustic fundamental, btw. A center signal fluctuating 1% in level on both channels simultanueously is
perceived as much more stable than the same signal with 1% independant channel fluctuation. All of this you can try yourself in case of doubt.
For the same reason, static rematrixing 2-channel content to 3-speaker L-C-R playback (like trinaural rematrixing) is beneficial. The center content "materializes".