I have always grounded my plugs one at a time with a jump wire to prevent ignition damage? Is it easier, simpler, and safe to just disconnect the pin connector to the coils? Then I can just leave the wires hanging instead of putting the plug back in the plug lead and grounding it so the spark has a place to go.
Or, with the kill switch off, you get no spark at the plug anyway, so is this even a simpler, easier and quicker method to check engine compression? Just turn on the kill switch,(stopping the ignition), and remove the plugs, then check your compression? And also disconnect the fuel pump so it is not dumping fuel into the cylinder giving false readings?