If that doesn't work I think it's time to play the SceneNodes card
But I didn't manage it to work because there's some bug with polygon selections running around that prevents me from using capsules as I want.
The plan was to make the following
PolyFX does its thing but this time you have two Dividers. One that is having the geometry changed and to make it look like small cubes by simple Inset and the other playing the primary role. The Delete would delete polygons around the Inset to make it look like a smaller polygon.
Both are under a Voronoi to convert all individual islands to instances and the Inheritance will link the scale from one Voronoi instance to the other Voronoi instance...
But I still have my doubts this will work because the plugin is in charge of changing the size of polygons not the Voronoi and not necessarily by scaling them...
Maybe this can be solved with XPresso but I have no idea how to use those 4 nodes.
Making clones scale to their assigned polygons' space is an old suggestion I sent MAXON. Blender has it, Houdini has it.... Even ZBrush has it.