Call for Artists, Making Money at Juried Art Fairs, Craft Shows and Festivals
Pro Panels are carpet over Styrofoam. What you need to do is create your own heavy duty strap hangers that go over the top of the panels.
Another option might be to use the appropriate size piece of 1/2" plywood mounted onto the straps. Then you could use the French cleat (Hangman system).
Note : I have 2D wall art that is a bit too heavy for standard pro panels. The solution for me was to make my own pro panels. I used two sheets of 3/8" plywood cut to the needed dimensions. Between the plywood are spacers and basic metal conduit (@ Home Depot) for legs. The folks at pro panels supplied the feet and tent hooks. I did have to outsource custom made corner and in-line panel joiners...that was kinda easy for a pro metal fab shop. The fabric to wrap the panels did get kinda pricey. All in all, I have about the same investment as stock pro panels. And the weight of the combined panels acts as it's own anchor to terra firma. Love em...a tad bit heavy, so I'll probably hate em in ten years.