Dunno the actual answer for a DMC, but the electronic brains of the unit wouldn't draw much current at all. A few milliamps I guess.
The coils would draw a few Amps each though. That coil primary current is switched via the ignition box. Some electronic ignitions have higher tolerance for coil current than others. The installation guide for most electronic ignitions will normally specify an optimum (or minimum) primary resistance for the coils to be used with it. Lower coil resistance than specified means a higher current that the ignition has to switch, which could fry its circuits.
I find it simpler to imagine a points ignition system to figure out what goes on. The actual current that flows through the an energised coil doesn't change with time. The current either flows or it doesn't, depending whether the points are closed or open. The time the coil is energised (dwell time) is determined by the number of crank degrees that the points are closed, so the actual time interval that the points are closed decreases with increasing revs, as does the points open duration. So the coil is always energised for the same percentage of time, regardless of revs. That means the average current draw is roughly constant throughout the rev range.
Some electronic ignitions have two lobes or magnets on the rotor, one to switch the coil on, and one to switch it off, so it works pretty much like points.
For electronic ignition units that have a single rotor lobe and a fixed dwell time in milliseconds rather than crank degrees, the average current flow through the coil will increase with revs because the coil is always on for a fixed time, but spends less time switched off between firing cycles at higher revs.
You'll have to ask a DMC specialist how the system figures out its dwell. Then you can then estimate the current flow through the coils by applying Ohm's Law to the coil primary resistance (I = V/R). Multiply that by the fraction of time the coils are energised and you'll have an answer (of sorts) for average current over time. It won't be a perfect answer because there may be a better way to work out average current. RMS (root mean square) is the preferred arithmetic for sine wave signals, but a coil current profile is roughly a square wave, so arithmetic average will be near enough. I suspect you're only looking for a ballpark figure anyway.
There are also other factors that come into play such as coil reluctance and saturation. But that's getting into stuff that none of us want to know about. ???
