Nope. Not that I have seen. The tracks distribute the weight well.
I would definitely consider the Rhino Rack system as they sell it as a kit and for quite a bit less than Yakima and Thule. I got the 59? bars. You cut the track to fit. The main reason though the rhino rack is optimal for the classic tonneau is because you can adjust the mounting bolts to wherever work best since the classic has large support ridges on the underside as you can see in my photos. Best of luck to you!