@mijostyn I have had plenty of suspended turntables, for many years from the late 70s a Linn that I was forever having to re-tune so that the springs bounce evenly. Then a Simon Yorke Zarathustra a massy design in which the springs were like car valve springs. That worked better. You may find it interesting that after that Simon stopped making suspended TTs, with the S7 that I used for a long time. You may recall this was Michael Fremer's reference for some eight years before he moved out of my league into $six figures TTs. I now run his S10, again solid, on which I hear no noise in an unmodulated groove.
You say vibration can pass through a heavy mass. This is true but only for large vibrations. Your example of an earthquake (caused by seismic movements, not by vibrations), is extreme. Yes an earthquake may spoil your listening. It may also bring your house down around you.
Small intensity vibrations of the type we are talking about do not pass through large masses. To pass through such objects the soundwaves must move it = vibrate it. They cannot do that because they are not sufficiently intense = have the power.
I do not hear footfall seated as I am on a concrete slab covered with carpet.
But there is no need to create problems by having a suspended wooden floor in your listening room.
frequency our own senses can detect but not the cartridge, it feels everything. That is what it is designed to do.
So, clearthinker, throw away your Kuzma Stabi XL DC AIR and get yourself a real turntable like a Sota, Basis, Avid or SME and enjoy listening to music without rumble. It will be an entirely new experience for you.