I did an install at home and posted pictures. Ours is a mandrel bent box tube piece which is very nice. Can you make your own, yes. Can you find someone to mandrel bend box tube, probably not.
Even though I personally did not shell out the bucks for surface plate testing of our unibodies, XV did. I really find it amazing how 4 years later people forget. Nobody ever thought of/cared about this until it was done and advertised. Our unibodies, although better than the B/E becuase of the smaller size are amittedly better than our Ford/Chevy competition of the era. However, compared to todays cars, its no comparison. Our cars are a wet noodle compared to any modern car. If you think the sheetmetal K, or the flimsy original rad support do anything significant to tie the front rails together, you're sadly mistaken. While some of the products XV makes may be controversal, the chassis stiffening is EXTREMELY effective, period.
I mentioned this earlier, as we have just finished the Duster/A Body Cuda 108" wheelbase subframe connectors and are looking for a 111 wheelbase car to use for templating. My car is not a candidate due to old frame connectors already welded into the car years ago. The 108" connectors are in stock now.
I feel personally, that chassis stiffening is super important, and a great investment any way you slice it.