Can you explain the reasons of going U hook instead of J hook? I only see downsides like holding the device upside down (so, holding from the U bend which gets hot?)
The heat will be hottest in the glass at first contact. In the J hook, in the photo it's right at the bend, which is where you'd naturally want to hold it it. I wrap my hand a little higher because of that.
With the U hook. I could hold it by the far side of the U.