In that situation the cable needs to be strong along its length but allow passing through orthogonally. Whereas a gear would need to be both strong and weak on the same axis.
I agree the implementation isn't sound, but there's nothing wrong with the concept of a shaft passer.
As an example of why it is conceptually feasible, remember that you could computationally (or mechanically) determine when a shaft is closing in and open a gap in that particular support at the right time, maintaining ability to pass torque through all other supports.
As an example of why it is conceptually feasible, remember that you could computationally (or mechanically) determine when a shaft is closing in and open a gap in that particular support at the right time, maintaining ability to pass torque through all other supports.