The one other attempt at this that I am aware of used a large die to form the bend and the result was cracking. The compromise here is that the bend isn't as clean as might be desired or required. But for a one off home project, the multiple bends with the little steps might become more acceptable when there is no longer another option.
For all I know getting to the final bend on the second piece will do the same. I feel like I pulled off a miracle the first time so I'm extremely hopeful the second bend will work out as well but at the same time very nervous for the final bit.
For an experiment I may take some of the extra length, the area where the trunk hinge goes, and put it in the press and keep cranking till it breaks. Not sure if it'd make me feel more confident though or make me realize my margin of error is zero. I'm assuming I'm playing with fire though given the thickness and the bend radius.