The key part of the mirrored skate block system is the redundancy of the braking system. Using the Petzl I’d as the controlling system, the system can be controlled by using one hand. This is a common practice in rappelling … why not here? With the anti-panic operations within the I’d, the simul-braking system is a no-brainer.
Make sure your have a knot at the back of the ropes… just in case the end of the rope should even remotely get close… But of course, you knew that:)