Here’s a short video to illustrate how my mix control reacts from LO to HI, coming from the same settings I used for the comparison with your video. On the LO position the effect is fairly subtle, the middle position is actually somewhere around 11 o’clock, and if I turn towards the HI position the effect gets less and less until it’s completely gone in the HI position. That can’t be right, can it?
http://www.falckenberg.com/downloads/Quaverato/Harmonic-Mix.MOV