Wow! All this just to shut off an engine, I'm impressed. Not trying to stir the pot. Just my observations with back firing or dieseling Commands. I've had some that as long as I let them cool off for a minute or two were just fine at idle, some liked 1/2 throttle, one I had to pull the choke and turn it off at the same time. I don't think that the shut down solenoid instantly shuts off the fuel, reason I say that is if you try disconnecting the kill wire to the mags and then shut it off it will run for a short while before it actually runs out of fuel. I have a neighbor with an MTD that has a CV20 in it, she insists on turning off hot even though I have told her not to do that repeatedly, still can't figure out why the muffler hasn't blown out. See what works for you is my suggestion. If you can get it to behave at idle that's always the best.
