Wow, Rusty that's some heavy duty reinforcement job! I just had my weld guy reinforce the frame on mine last week. He assured me his (mild by comparison) triangulation of the pinch as seen here would be more than adequate and would outlast the frame. There were a few small stress cracks which he also closed up.
I originally told him I wanted him to bend a 24 inch long angle iron and weld it along the outer bottom of the tube but he said that much welding would have the fire dept hosing down the
Burro. OK, I said, you're the expert.