If the frames are breaking this easy, they are junk. Back in the day, (I Know), we used a truck like a truck, and never had frame trouble.
Almost every truck I bought, I put an extra long leaf in the spring pack plus a set of the bolt on coils that bolted to the rear axle and the frame dropped against them when loaded. All were 1/2 ton, 2WD long bed trucks. When it snowed, I would go to the store and load a 1 ton pallet of shrink wrapped lime and go anywhere, usually to the mountains. Never any problems.
I hauled or pulled anything I wanted. Loads of 1 ton plus were common. Never had a frame issue. Maybe it's because all those trucks were Fords?......NO, had an '82 Ram I did the same thing with.
Heck, we put a one ton pallet of fertilizer on the back of a 1980 VW pickup and transferred it from one store to the other over 10 miles away. It was dragging the ground and the 'ole diesel was pouring the smoke, but it made it.
My point is, these new frames are sub-standard. This is a truck we're talking about that's made to haul things.