Obviously, electrical noise(s) generated by computers and SMPS are an inherent issue in digital computer based audio and impact playback. [...] I welcome any feedback and potential suggestions that don't involve a drill press, a lobotomy or narcotics.
You may want to consider counterexamples. As far as SMPS, IMO you would need to have a very, very resolving system in a very quiet room to have a hope of hearing the noise generated by a competently designed SMPS. By rectifying a higher-frequency AC signal, they make it possible to filter the DC better and
reduce noise. Of course, cheap wallwarts may in some cases cause problems, but, e.g., the Classe CP-800 preamp has a well-engineered SMPS. and it's ranked quite highly by many, including John Atkinson.
As to electrical noise from computers, I've never heard network-streamed audio in which such noise was audible. Indeed, I think you'd have to have a system like Robert Harley (and a dedicated, acoustician-designed, silent room to match) to hear these things -- if you could hear them even then. I've heard USB-connected systems that sounded better than those with no computers. It all depends on the design of the connected equipment, IMO.
Why, then, is "everyone" convinced that such things are true? Well, manufacturers are looking for something to sell and points to make in ads, and magazines are looking for something to talk about. Audiophiles are always looking for a quick fix, rather than doing hard things like building a wall around the refrigerator or installing acoustic treatments or treating room modes with DSP or repositioned equipment.
So while SMPS and computer *might* induce noise in a system made up of poorly-designed equipment, in my experience, they are not the major sources of noise that outside traffic, HVAC systems, the refrigerator in the kitchen, the fan in a computer or piece of audio equipment, or a humming transformer can be.
