Both CDI and transistorized CX`s have a wasted spark ignition system because they both get their timing pulses form the crankshaft not the camshaft.
The crankshaft doesn`t know whether it`s on the exhaust or compression stroke so you get the spark plug firing every time the crankshaft-mounted firing doo-dah sweeps past the pulser - once every crankshaft rotation/twice per four stroke cycle.
Cars for example have distributors which run at half engine speed/off the camshaft so each plug only fires once for a particular cylinder and thus do not have a spare spark system.
I think i`m right in saying the CX Turdo`s have the ignition pulser plate and the triggering `pip` mounted on the camshft (in a separate housing behind the water pump) so they also do not use the spare spark ignition. I suppose that extra spark during valve overlap at the end of the exhaust stroke is undesirable on the blown CX engine?