Unless I'm missing something there is no way to set-up a quick drag and drop style cable placement.
Ideally I'd set the standard that the components use such as a sensor with two M12 connectors for Data and power, I'd also set the standard for the IO box ports as well. Then I would select the two points and it would generate the cable and appropriate connectors. The spline length would be pre-determined, and I would just need to set face offsets and clip locations to determine the spline path.
But it doesn't look like this is the intent of the harness module, it wants to map the individual pins.
It almost seems like fudging it with the tube and pipe module would work better if all I'm concerned with is routing and looks.
This is all new to me, so if I have it all wrong let me know.