Tesla, those cooler panels are manufactured in a variety of ways. Some brands do not have any formwork in them, relying instead on the folds in the sheet metal at the seams to hold it all together.
I've seen both aluminum and stainless 'skins.' The question we're asked is: How do you mount stuff to it?
I don't like punching all the way through, as that often introduces other issues (like water leaking). For heavy loads, that might be your only option.
Sheet metal screws might work fine for conduit straps, but boxes and fixtures will need more. You might have to hollow out the area behind your holes in order to use toggle bolts.
