Let me throw a mokey ranch in here. When you place a cable between two supporting point, doesn't that create a classical string boundary problem. Just like a string instrument, now the cable can behave like a string with its own resonance frequency and is excitable by certain frequency vibration? Does that in turn means that the number of supporting points can alter the frequency response? The mechanical and electrical interaction of this system is not trivial.
I tried to elevate my speaker cables with disposable cups and it made a sonic difference. Images were more forward than before and I could hear more detail, but I lost some musical warmth. So I removed the cups. If some one has a better mouse trap, let us know.