I haven't read thru the whole thread so this may have been covered. And up front I am not a believer in high dollar cables in an "average" set up. Better cables yes. Digital 1's and 0's are voltages that can and will be affected by material like any other voltage. Ohm's law is your friend. Then you have shielding for interferences. I work on digital controls for power generation and there are many factors we have to deal with to get good ones and zeros to and from equipment and controllers. It does matter the question is how much in your situation.