I haven't tried a direct pulse spark plug device nor a resistor spark plug or a resistor plug wire.
I thought they might or will not work but you guys can try them and see if they will, if they do work then that is good news less RF noise to drive the neighbors crazy. If by chance your lights kill the engine when you turn it on and your running any one the the resistor parts you might try the lights with out the resistor parts.
I do know if your spark plug is close to fowling out the lights will find it for you as the engine will die with the lights on while your riding along, turn off the lights and the engine will come back to life. You will then need to change out the spark plug for a new one. It will only happen when your out someplace in the dark and no spare spark plug or plug wrench, Murphy's law applies.( some cussing allowed/happens unless your not one to do that,for me NO comment.)
I was guessing that if you use a resistor device with a weak mag coil the spark plug might not fire when using or trying to use a light powered by the engines mag coil white wire.
Thanks Goat herder for sharing your findings with the set up your running!
Norman

me working on the bike. Don't touch the spark plug when its running, it is a very enlightning experience!!!!!!makes me twitch funny.