I must admit I've seen mention of that a few times on my 'Journey' but never fully understood it. My way of thinking of this is that the ignition ECU should turn the coil on (ignition driver allows a path to ground) only when it wants to fire. This should happen a period of time before the spark is required where that period is equal to the dwell time (3ms fixed on the Nodiz I believe) at the end of the dwell period it should go open circuit. So unless the system receiving a CPS input it should not turn on at all so the coils should be safe, even if it does turn on it should only do so for 3ms.
Maybe I'm missing somethng? And I do disconnect my coils when I'm 'playing'
The only way I can see that the coils could be left turned on is if there is some other path to ground, this is one reason why I don't really like having those diodes there. If there was a path to ground through them either due to a wiring fault or in the 14CUX ECU they could be left powered.
I don't know how 'odd' the 14CUX is though in that it requires a high(ish) voltage signal to detect the ignition pulse, perhaps other systems will work happily with a 0-12v square wave which the Nodiz does provide although that is NOT at the correct frequence for a V8.
Must admit I did get the feeling that the Nodiz is designed for 4 cylinder engines and has then been 'bent and twisted' to work(ish) on a V8 but not really properly integrated. If it works great, if not hard luck is the impression I got.