Speaker cable geometry question


First of all, I'm sure this has been asked somewhere but I couldn't find it.  I have been out of the loop for a while and have just gotten back into the hobby and am looking for an answer on this (because I am just curious).  
Most speaker cables consist of any number of geometries in a single run from amp to each speaker in a single sheath.    Some however have single runs of + and - to each speaker.  Such examples include certain Purist cables such as Dominus and Neptune, Jena Labs and Nordost.  I am sure there are more but these are the ones that came to mind.
What is the advantage or disadvantage of doing a cable run in this manner.  These are very expensive brands and I've been rekindling my interest and this is one area in which I have developed a particular curiosity. 
nutella
But the cables don’t carry the audio waveform. They carry alternating voltage and current, neither of which are related to frequency. So as far as the skin effect being used in any theory of cable construction pro or con I frankly don’t get it. I do understand why AudioQuest highly polishes the surface of wires and honors the inherent directionality of wire. That makes sense.
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Cables don't directly change midrange only, but moving speakers to change wires often does.
Speakers are in the exactly same marked location, angle etc.  Nothing changed in the room.