Alright.
Is there a value in monitoring product temperature? Sure. The product is the ONLY reason that we have refrigeration. If there isn't any product in the case, then we might as well shut it down. 100% energy savings.
Now. How will monitoring product temperature help us to save energy? By cycling the refrigeration based upon product temp rather than on air temp? BAD IDEA.
We'll see wider temperature swings and more energy will be consumed in pull-down after pull-down rather than a steady, even temperature control.
There's another reason that this is not going to work out.
Anyone who has worked in the retail refrigeration sector for any length of time will know that the employees try to CHEAT. They'll shove warm product into a case any time they think they can get away with it.
What that means is that this thing is useless. It will be reading the "steady state" temperature of the case. The temp that product
would be if everything was done properly. Since everything is almost never done properly, it's a big waste of money.
Of course, those that deal in 'thermal inertia' and other equally spooky and mystical language have great sales pitches and those that are in the market to buy such things have defective BS detectors. A match made in P.T. Barnum's version of heaven if there ever was.