I've never heard of suspending speaker cables. . what's the rationale behind that?
There's several. Most likely the main one is vibration control. Check out my system, and don't take my word for it but read the comments from people who have heard it. Deborah for example, had no idea, heard it with her eyes closed. https://systems.audiogon.com/systems/8367
This is also a good example of how to do a system that maximizes performance per dollar by minimizing wire length, among other things.