[Christ]

Yes and no... you'd have to test very carefully as some engines really DON'T like lean burn conditions.

Also, the average temp, like I said, won't give you an idea of whether or not one cylinder is in danger, which is quite the possibility, due to manufacturing differences. You could technically be at a lean mixture that is best for one cylinder, and deadly for another one, and you wouldn't know that based on a single temp sensor/switch.

If you were testing very carefully, You could use a single switch/sensor to kick on an additional injector or something that would add water/meth to cool down the intake charge, but you'd have to be doing testing in small increments, as you wouldn't get real time data from each cylinder.

Using either way, you still won't be able to detect hot spots, which are a primary concern when considering a/f ratios. (and in general)