Just control the coil from an aftermarket ecu, like megasquirt. You can retain the bosch ignition module to retain the original dwell values, or program the dwell into the ecu and remove it.

Our CIS-E system originally had a knock sensor control unit (controlled ignition) that communicated with the oxygen sensor control unig (the fuel computer). Initially we just removed the knock sensor control unit and ran fixed timing. Then came back and added programable control to tirgger the stock hardware.