I don't know if I understand your question completely, but basically "Rig balancing" does not introduce a new parameter to the presets, it is more like a different way to check one parameter that is part of every preset: the rig volume. If you go to "Rig balancing" you will see a list of your presets and there is just one thing you can adjust: the rig volume of the preset which is currently chosen. Choosing is done with the increment control and the parameter value is adjusted with one of the knobs, as always. When you chose the next preset, it is being activated so you can play the sound and listen to the volume. If it needs to be adjusted, turn the parameter knob. Then use the incremental to go to the next preset and adjust that. When you're done with all adjustements (you can even go back to the first or second preset to check again) hit the "edit/back" button and THEN 11R will save all the changed rig volume values in the respective presets.
This is the same thing as if you would call each preset with your foot controller, hit "edit", scroll to the volume block and adjust the rig volume. It is one and the same parameter. "Rig balancing" just offers a more comfortable way to adjust the levels of many presets quickly including the option to directly compare them.
I hope this makes the function clearer. It is one of the best features of 11R, particularly for live playing. It has saved my ass many times.