In both photos the break occurs at the point in the clip's slot exactly where the bolt ends. I suspect this is due to a weakness at this location that is induced by the welding process. In the other parts of the weld, heat is absorbed into the stud and the clip. At the very end, there is no stud to absorb heat, so the clip will take all the heat and get much hotter here and oxidize more. This may be fixable with a post-weld heat treatment, or the weld should end a few mm before the end of the stud. I'm an engineer, but not a welding engineer or metallurgist, so I think I know enough to ID the problem, but not enough to confidently solve it myself (big help, I know). Hopefully the rack manufacturer has consulted with both for these new clips. This should be a very solvable problem, as these are not exotic materials, enormous forces, or an unusual geometry.
Personally, I'm really hoping that Yakima will use this J-clip geometry to create an adapter for their landing pads. I want a solution that I can install and remove in a minute or two with no tools and no adjustments. I'm happy to have four little pods on the roof when the rack is not there. I love the functionality of the Skyline system!