I actually had to ask someone about this, someone into Toyotas, because Misfire Margin is a proprietary Toyota figure of merit for debugging misfires. Fortunately I know an FJ fanatic who understands automotive technology. Misfire Margin is not a probability factor for a misfire occurring, in fact THE LOWER THE MARGIN THE BETTER THE CONDITIONS ARE IN THE CYLINDER FOR A MISFIRE TO OCCUR. Apparently the way the FoM is used is that you vary the engine speed under load, like driving the car around with their diagnostic software running on a laptop plugged into the OBD port, and look for conditions under which the Misfire Margin goes down. Based on those "low margin" conditions you note other actual measurements, like air-fuel ratio, to get indicators for further problem-solving. So in other words, Sheep, Misfire Margin is an inverse indicator. Values *above* 30% are normal, while really low values point to a condition that should be further diagnosed as possible causes for misfires.
Anyway, Sheep, you have completely misinterpreted the meaning of the data, again pointing to the reality that you really don't know what you're talking about. As for a Christmas present, how about just sticking to what you really know?