This is a toggle on the supercontrol options page as well as the subcontrol options page.
Subcontrols of the supercontrol will send their current value instead of having their value affected by the supercontrol.
Note that this may also be specified per subcontrol, which is probably more useful:
Typical Use Case
In the case where you are using a bank select and program change as subcontrols ( see here ), you might want to "dial in" (set) the value of the bank select by hand. Then each press of the supercontrol would cause the bank select to send its current value (the one it was set to "by hand") and the program change would send its on value, or its MIDI max (scaled to the MIDI max of the supercontrol).