My thinking is probably not. But it is cheap and easy and can't hurt. I currently don't have my DAC on springs. I have had it on springs befor and likely will put them back under it.
The pseudoscience over at ASR has people focused on measurements. but as a physicist, I'll tell you that i've taken millons of measurements and have a good idea what can be measured and what can't. The subleties assiciated with amazing audiophile sound are not something that I've ever seen quantified. I remember in the 70's it was all about one little number: every reciever had to publish their THD number. Now we find that was never a great guideline. I guess it was an indication of attention to detail by the builder but that is all.
So I base my decisions on my understanding of the physics around the issue (which is usually pretty good, I graduated U of Chicago in physics in 1980 and have worked in techical business for 40+ years) and what I hear. So for isolating your DAC, I consider is a very minor tweek with very little liklihood of much improvement since solid state electronics are very stable in vibrations. However there are wires and power supplies and maybe some exotic components. So why not.
This tweek, like many others we do it minor, trying to get that last .1% of improvmeent and many of these tweeks are not immeidately audible. but do 5 or 10 of them and maybie it will add up. If a listener does think they hear an imediately audible change after a tiny tweek like this, I suggest they think about whether they are experiencing a confirmational bias. but occasionally a small tweek fixes a weakness in the system and voila, improvement.
Jerry