The IGN out should only be the BLK/WHT to power the coils. The RED for the ignition plate should be wired from AUX.
Understand that the RED is seeking a power source from the mUnit to excite the Dyna. The IGN out is powering the coils. If you feed both the coils and the Dyna, their combined draw will exceed the amperage of the powered-out circuit.
So yes, split them across two circuits and you should be fine.