computer isolation

I'll go out on a limb and say no. If you're output is a digital signal then no for sure and if your outputing an analog signal then I doubt there is any level of isolation that could improve the signal.

Unlikely unless your laptop has tubes or uses a stylus to read a vinyl groove. Modern electronics is not micro-phonic. Frankly, if it was a problem then passive speakers would not work as the crossover would pick up vibration.

Just another urban legend.

Urban legend? I do not know if it will make a difference, but most all electronics are sensitive to vibrations as they have capacitors aka condensers- as in condenser microphones amongst other things.

Crossovers are micro phonic as well, just less perceptive as the signal is very small relative to the load. The Tannoy DMT series of studio monitor loudspeakers for instance. DMT was market speak abbreviation for Differential Material Technology. The capacitors were all wrapped in a butyl rubber type (mortite?) compound that had heat shrink tubing around it to help suppress the vibrations.

How much of this effects the output is up for debate. Acting as if it does not exist is a falsehood. Physics has not changed, only our applications of it. As for the OP's question, there are probably more important things to try to optimize in you computer audio rig.

I must admit that when I first thought to try putting my Mac server on and isolation rack, StillPoints, was that it would make no difference but that it was convenient. It made a big difference and has stayed there. Furthermore, more recently, I have put the new StillPoints Ultras between their rack and the Mac, again with a major improvement.

I strongly suspect that conductive wires moving in a magnetic field being dampened by the isolation is the explanation for why this is happening. I a shocked at the negative impact of even minor vibrations on the magic in music reproduction. All I can really suggest is that you try it to see if it holds for you.

As for the OP's question, there are probably more important things to try to optimize in you computer audio rig.

Exactly my point. The extent to which vibrations affect electronics has been greatly exaggerated due to people's experience with tubes and stylus (with a very high gain which is why you have a pre-preamp). These truths have created an urban legend in that people have extrapolated this to conclude that micro-phonics are a potential problem with all equipment - generally you don't have to worry about micro-phonics on a PC - although the physical noise of the cooling fan and the spinning of the hard drive can easily be an audible issue (especially if you sit next to the PC).