Curious why the probe is in the middle in the air?

I understand that's not the issue here, just that I've never heard of hanging it

I taped my probe under the flexwatt in the back of my mini fridge, what's the advantage of hanging it?

The amount of flexwatt shouldn't matter(unless there is too little), only the setting of the t-stat.

I used 2 feet in a 4 cubic foot mini fridge, worked awesome.