Not trying to hijack this commentary, but I felt this is particular to both your problem, and mine.
JBarca pics of his earlier HD snap up made me go look at a few differences with my much older ones. Mine are '03 vintage, and my son's are '05 vintage and are exactly the same. His setup was 1000# which are the bars I was using when my hitch cracked. Notice the differences: higher chain hook on old, and closer in to the frame. Hinge point is higher and further out than the "HD" style. The metal bar clamped is positioned where the frame would meet the snap ups.




So my thoughts are: How much more or less twisting force is applied to the trailer frame under normal towing events, which would include turns, driveways, twists and turns, by each of these snap ups??? Which would be better for these new, weaker trailer frames???
I think the older style would be less prone to have a failure. I know I have had one fail with the new hitch, but I still believe there was something abnormal happening during the first setup. The snaps and bangs were way out of line.
Appreciate all your thoughts on this, esp from you and JBarca!!
Gerry