May I slightly correct this: when you're in Rig Balancing mode, you can scroll through your presets using the scroll knob. But to save the changes you made using the parameter knob below the display you need to leave Rig Balancing mode using the edit/back button. This will let 11R go through all presets you have just changed and store the new values, i.e. overwrite the previously saved ones.
I do use Rig Balancing frequently on stage, because having correct levels between patches is the most difficult thing to do and besides having an expression pedal to jump on for quick corrections Rig Balancing is the most important tool.