It is painfully easy to tune CIS-E.

Get yourself a 0-10k linear potentiometer. Install it in line with the coolant temperature sensor. Go to a dyno and make some runs while measuring air/fuel ratio with a wideband O2 sensor. Turn the potentiometer until you find the optimum setting for power (typically 12.7:1 on these motors). Measure the resulting resistance, and replace the potentiometer with a fixed resistor of that value. People use different methods of switching this enrichment device into and out of the circuit manually or automatically based on WOT switch.

It is consistent, reliable and functional. One thing you are giving up to a programmable system is ignition mapping ability, but in the racing operation range you are typically at max timing regardless of the lower load/speed maps, making this a moot point.