Just tried this on my own.

I first changed Will's figure name. Then I loaded the original VSS prop, created a new figure rule* to match the new name for Will, disconnected the nodes associated with the eyes, then saved the new vss prop.

I loaded Will, loaded his VSS prop, synchronized, then deleted the prop.

Then I loaded a Kids 4 figure, loaded the Kids 4 VSS prop, synchronized.

The render shown looks ok as far as the eyes so I assume what I did worked. Only thing is the skin tones do look a bit different from each other.