Hi Parrotbee,
What Halcro says then explains why people like Mike Lavigne are using very expensive microscope stands in their systems.
If you talk to those who have changed to a wall-mounted shelf or active isolation stand or concrete slab-on-the-ground installation....they will likely express amazement at the reduction in noise-floor and the silent 'blackness' they now hear through the turntable system.
My vinyl playback system is quieter than CD...😎
An easy test for any turntable whether mass-loaded, suspended, plinthed or plinthless....is to place the stylus on an unrotating record and gradually turn up the volume of the preamp.
If a droning feedback sound commences and increases without further volume turning.....you are hearing Structure-Borne Feedback through your floor and/or rack supporting medium.
If you are able to turn your volume to maximum with total silence (even when lightly tapping the plinth)....you are probably free of feedback issues. 😘
Good luck....