You will be fine with one sensor. If you want to see for yourself, then just weld a bung in each side and switch the sensor back and forth. It will only take a couple of minutes to do and you will quickly see that both sides will read close enough to each other. It might be a good idea to have the tech rep send you a pic or two of the graphs that they produce. Study them a bit so that you understand them. Do the same with some other brands for comparison. Because it is the graphs that are the key here.

Does this unit self smooth or average or at least have a manual smoothing or averaging function? I didn't see it mentioned in the description.

Here are a couple of links to tuning sites. They are primarily about using Innovate products, but they provide a good look at carb tuning.

http://racingfuelsystems.myfunforum.org/

http://britishqueen.myfreeforum.org/