That makes sense. After more thought, the cylinder pressure should be close to ambient during the second spark which will effectively inhibit any ignition.

Another post suggested a price of $230 for the conversion (in Japan). I wonder what it will cost here in the US, and if/when it will actually be available? The increase in weight caused by the ignition module will be more than offset by the decrease in fuel load required. With the decreased fuel consumption this mod will pay for itself rapidly (within 15 gallons of fuel burned at todays prices...).