@pindac, using the word ’cornerstone’ like this in relation to turntable footers is tricky. For stability you’ll need 4.......
Anyway, while upper vintage turntables (DD or otherwise) are still competitive, in most cases their designers didn’t spend too much thought on plinths and footers. There are exceptions like Pioneer P3, where the wood veneer plinth is more like a skirt over some very elaborate suspension. But in most cases the footers just have some type of resilient material to absorb external vibrations, including the earth’s plate movement as some seem to believe.
My appartment has wooden floors and in such a case these resilient footers are totally inadequate to absorb foot falls and other floor borne vibrations. Wall mounting is the only way to go. When you have eliminated the floor as a source of vibrations you don’t need resilient footers and you can change to mass loading the table.
Consequently, my tables are all wall mounted and have their original footers replaced with non resilient ones. In every case the sonic improvement (in terms of tighter bass response, cleaner highs, dynamics, etc.) was as obvious as can be. I use Finite Elemente Cerabase Compact footers, but I’m sure there are plenty of alternatives that will give the same result.