I don't understand.  What's the benefit?  It looks to me like he doubled the weight, made the water cooling much more complicated, and added zero power.

-The Mazda design uses coolant to transfer heat from the spark plug side, which is very hot, to the intake side, which is very cold.  This helps keep the engine from turning into a banana.

-The Mazda design has the two rotors on opposite sides of the shaft, so that they counterbalance each other somewhat.  The counterweights would to counter the offset weights in the third dimension.

-In the Mazda design, the two rotors share the two ends of the shaft for driving accessories on one end, and output power on the other.

-In the Mazda design, the two rotors share an oil pump

-The Mazda design the two rotors share one of the side housings.

-It would be no more difficult to fit counter-rotating props to a Mazda than to this.

Nice CAD work, but did he discuss any possible benefit he's expecting?