The issue with placing the Red Line Keys on the Black Line is that it only works if you can only have TWO layers. If you have more the TWO layers and they are in an ADD mode then you have to figure out where the line should be. Below is what happens if you just add 2 more keys to the Red Line in poser 11.

Notice the new Key at 12 drops below the Black Line. The Key at 17 Jumps way above the Black Line, about where it would be at Zero if the Black Line stayed as a straight line.

TO my way of thinking as a programmer if they get rid of all the fancy code trying make the Red Line track the Black Line then it will make the whole thing simpler and probably make it work as it was intended. The only issue I can think of right off hand is Master Parameter dials that change the channel values, things like a make a fist which changes all the finger channels indirectly.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13