For the VCS layout where you would like to have toggling behavior, change the widget type to Vertical Radio Buttons. Then set the button labels by unlocking the VCS, selecting the widget, and choosing Set Labels from the Options drop down menu in the VCS editor. Set the tick mark spacing to 1, choose the list labelling scheme and set the labels to Off and On (for example).
This would keep the fader continuous on the other VCS layout while making the control discrete on this layout.