Meta I have never used large/massive cables like the big snakes or BMI whale, but I believe they can work if they are very "flexible & twistable". Cables must hang and apply no push/pull force, "stiffness" is the biggest problem as it hinders free horizontal sway of bearings. If you have a very large flexible cable you can make some type of cable tree/support/suspension behind rack to help nuetralize weight of cable if needed. For heavy cables I would definitely put two bearing devices in back and one in front of component to support heavy cable. The light cables I have used just hung freely from gear behind rack.
For instance I could never use bearings with SR master coupler AC cord as it is stiff cord and always pushes
the component it is attached to, defeating the bearing
devices. The Shunyata Sidewinder on the other hand worked fine because it is flexible and lightweight, allowed
free horizontal movement of component. I have since replaced
my Sidewinders with Absolute cords, which sound better and
are perfect for bearing suspensions.
Rollerblocks are more forgiving and slightly more tolerant
of cable issues compared to MIBs, but still need nuetralized cable forces to work properly. Obviously lighter/flexible cables are ideal for bearing application
but larger very flexible cables can also work it set up properly IMO.
Hopefully someone who has a large snake can respond with their set-up/use experiences, as I have no direct experience. Best to use common sense and just try one set
to see if it can work with your cables/rack.