Here is how they are mounted.
One SW-Motech engine guard kit.
Some brackets welded to the engine guard from the local welding shop. Bolt Kolpin brackets to engine guard.
To answer your question, no, I don't worry about heat. The tank is sealed and expands more just sitting in the sun than it does when I'm running down the road. It is one of many options. Some people comment on it being exposed in a wreck, but it doesn't seem worse than a TT tank IMHO.