Well, just tested with another really mint L6 ECU - still no spark, tested combinations with all three ign modules.
Will try to remove the MSD and see if there's a problem there.

I tried using the magnetic pickup input on the MSD wired to the cps / tdc sensor, I disconnected the "-" from ign module. Now I got spark, so the CPS seem to work aswell as the MSD. However the MSD mag pickup may need a lower voltage to trigger than the ECU so will try to check cps voltage one more time.