Butcherblock Acoustics "feet" effecting sound and isolation

You don’t need to isolate components like that 

Those discs the spikes sit on should have a rubber disc glued to the bottom of it so that should offer some isolation. Blind testing would be the best way to see if something works or not. 

+1 @townshend-audio 

I use their isolation bars for my speakers with amazing results. I plan on getting more isolation from them soon. Simple and it works.  

This is another area that a little goes a long way and too much can cause more harm. Richard Vandersteen put out a paper on isolation for speakers. He expressed caution in having to much isolation based on the facts of the movement of the speaker drivers. The movement of the driver is critical to its function. The speaker has to have a solid stable base that allows for the driver to function and perform at its best. If the isolation detracts or takes away from the driver movement the sound and performance can produce bad sound. Experiment with options, let your ears be the judge but start small and know when the solution starts to be negative.