Hey I commented on your facebook post as well but I have not done this personally so will reply here too, to fuel discussion.
It looks like the design of that system is for up to four cylinders. The instructions say to tape off the unused green wire.
Based on that schematic it doesn't look like there is any difference between the green wires you just have to use 3 of the 4. The instructions also say it doesn't matter which coil you "identify" as coil #1.
Presumably this thing is just killing ignition to all cylinders when you shift so it really shouldn't matter which is which (I guess), maybe the only reason they identify 1 vs 2-4 coils in the instructions is to illustrate better how to install the system. For example how only one stock positive lead is connected to the new wiring.
Good luck!