radius expansion for multisphere clump

I was surprised to find that radius expansion can also work on multisphere clumps, but I noticed that the kinematic parameters (mass, mass center, moments of inertia) of a multisphere clump were determined and output on the moment when the clump was inserted. So I wonder whether the kinematic parameters of a clump will change dynamatically during the radius expansion process or just remain unchanged. Any hint is appreciated.