What's better, one conductor or two conductors for an RCA interconnect?

Is it better to connect the ground to each side of the RCA cable?

Single ended RCA cable, the ground is connected on both sides, there is no choice. If there is an additional shield, typically is it better to only connect it on one side.

@deludedaudiophile So, you are not EE.  Well, I am - designing low level electronics for 40 years.  Sorry I cannot explain it to you better.  We agree to disagree.

I have a PhD in materials science and close to 2 decades in semiconductors, semiconductor processing, and associate equipment, including forays into process measurement and control ... well exposed to signals in noisy environment. Doing much of the same in batteries now.  I understand the overall issues quite fine and could probably derive a lot from first principles. I understand your argument, I don't agree with all of it and I think you have poorly argued some points specifically as it may apply to real world applications including equipment ground connections and how they relate to loop resistance or impedance. Given the indeterminate ground connection and how that related to the loop resistance all due to the signal connector, I believe you are making erroneous conclusions about what would be common mode noise injection.

A speaker connection is balanced from the standpoint of the speaker, but if you induce noise on the speaker cables, it is not balanced at the amplifier input hence why the amplifier circuits for sensors and bridges, both often floating, are still fully differential circuits.

So it appears there are no clear Views on whether the ground wire should be connected to each RCA connector.  So you have 2 connectors connected to the RCA connects ans a ground wire connected to both RCA connects.  
 

So it is on this very point there is no clear rationale or consensus as to how the ground wire should be handled.

Personally I think this is really sad and should really frustrate those trying to choose the best interconnect.