I’m currently at Watkins Glen for the NASCAR race, being camping in a muddy field for 4 days I had to bring my Generators (two Honda 2000’s), my enxtended run tank (12 litre boat tank), a 4 gallon gas jug and two 4 gallon water totes. I was able to secure the fuel tank, and three jugs in front of the bed and both my generators out back on the passenger side, nothing is in the way of the hitch or the electrical cord and breakaway cable, worked great for the 900+ miles I drove between Wednesday afternoon and Thursday to get here.
If you secure your load carefully and properly out of the way from the hitch head and cord/breakaway switch you’ll be fine but it cannot be loose items as the wind will move it around.