Best Footers for DAC?

The effectiveness of cones in terms of SQ is primarily a function of the hardness of the material. That is why DH (Diamond Hardness) Cones sound better than brass, carbon fiber, aluminum, even better than hardened steel cones, which are all considerably lower on the Moh scale of hardness than the Space Age ceramic DH Cones. Having said that, the effectiveness of cones is also a function of the shape of the cone. Which is why Super DH Cones sound noticeably better than Jumbo DH Cones. Both are essentially the same size and weight, but the Supers have a more ballistic shape. 🚀 Is it cheating to cryogenically treat the cones? You decide. Yes, you want to drain vibration from component but you also want to decouple the component from seismic vibration. So BOTH techniques are required for best results.

@geoffkait What is your opinion regarding Sorbothane as posted in edstrelow's post above (12/2/17)?

Sorbothane seems like SUCH a good idea. But sounds pretty terrible, usually. Of course that’s just my opinion. If someone gets good results with Sorbothane or say lead, more power to them! There might be somewhere Sorbothane sounds good but I never found one. In fact I believe Sorbothane is the Poster Child for Expectation Bias. Like the metal lead. It’s a case of it looks like a duck, it acts like a duck, but it’s not a duck. Not all Viscoelastic materials are created equal. The trick is to find a good one and a place that works, that doesn’t choke the sound and make it weird. For headphones and such Marigo VTS Dots (constrained layer dampers) are the cat’s meow. And they’ve been around almost as long as chunky peanut butter. For transformers, capacitors and printed circuit boards, etc. I use Marigo VTS Dots and or cork and constrained layer dampers. Disclaimer - I sell a constrained layer damper and pure natural cork for such purposes. Unfortunately I cannot reveal the particular viscoelastic material I use in my product.

"scientific (mechanistic) reasons behind use of these for a DAC could include tribo-electric effects, or piezo-electric effects on any internal crystals in the DAC"

Aren't the crystals in DACs operate in MHZ/GHZ range? Isolation from mechanical vibrations would mean nothing to them.  I think the humidity/temperature/athmospheric pressure in your listening room would make more difference in the perceived sound than mechanical isolation of DAC.
Just IMHO.