Lets make this as simple as possible.
The turntable supplies the energy the groove uses to force the stylus to vibrate in any combination of two directions, up and down, side to side. In an ideal world the cartridge body would remain absolutely still. It would not vibrate or resonate at all. However due to the fact that the stylus is suspended from the cartridge some of this energy is transferred to the cartridge body. Assuming the cartridge body does not ring the frequency this energy is transferred at depends on the stiffness of the cantilever's suspension and the mass of the cartridge. If the cartridge is solidly mounted to the tonearm you can add the effective mass of the arm to the mass of the tonearm lowering this frequency which all agree should be around 10 Hz. Putting a flexible material between the body of the cartridge and the tonearm add a second suspension with another resonance point determined by the stiffness of the material and the mass of the tonearm assuming the tonearm does not ring. Since this suspension is obviously stiffer than the one supporting the cantilever and the effective mass of the tonearm is lighter than the effective mass of the tonearm plus the cartridge, this resonance frequency is going to be much higher. If it winds up in the audio band it will be audible and represent distortion. If it is above the audio band it will inaudible except maybe to members of the tweaky gang. Is such a device going to dampen any ringing? I suppose it could but I would rather have a cartridge body and tonearm that do not ring. Good tonearms and cartridges do not ring so adding a secondary suspension can either do absolutely nothing or add an audible resonance which is obviously not good.
