My proposed second generation "mid-chassis" box beam "stiffening" brace

The Cusco mid-chassis stiffening brace, with the two beams that go to the back brackets that hold the two parking brake cables, and selling for about $200 is definitely overpriced, overdesigned and overembellished
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The two arms that go the the back does nothing much to improve stiffness, given to their small sectional strength and long length of the "lever arm." A long thin "lever arm" equals limp and "whippy."

The massive (by compassison) 1.5x3 inch box beam that I use, has nearly the mathmatic "square" of the strength ratio when compared to the Cusco.

I have not seen the Cusco center brace in the "flesh," but it appears to be 1/2 x 1-1/2 of a rounded end oval box beam of what wall thickness, I don't know. But, it can't likely more than 1/8 inch wall.

Basically, my original 1-1/2 x 3 inch sectional box beam with a 1/8 wall will be approxinaltey 24-36 times as stiff as the small section of the Cusco cross beam.

I have decided that the original is vastly overbuilt and will make any future unit oiut of 1x3x1/8 wall 6061 T651 aluminum extruded alloy. This tubing will be at least 12 times as stiff as the Cusco material.
The Cusco has two welds on it. Mine will be one piece. This means that the Cusco must be 6061 alloy, since the higher strength allows such as 2024 or even 7075 are not availble in extruded tubing, and neither 2024 or 7075 are weldable.

The two welds in the Cusco brace also weakens the 6061 tubing, since high temperature welding destroys the the T651 temper and "anneals" the tubing.

Painting of 6061 alloy is not necessary even in marine environments. 6101 is commonly use for marine gas tanks and survives unpainted for 20 years or more in marine environments. You just don't want 6061 to lie submerged over long period of time in water. Basically, painting would be for looks and embellisment purposes only. The box beams of the Prius bumbers under the covers are made of aluminum and not finished,

A 6061 plate is in no way as strong as a box beam. The surface layers of tubing take nearly all of the tension and compression, when a box beam is bent. A 1/2 inch thick plate can in no way be as strong as a 1x3 beam, since a 1x3 beam is theoretically reaches the same strength as a solid 1x3 beam. The "core" is nearly dead weight and mass. It adds very little dynamic strength to the structure.
It's like this.

A sheet, even 1/2 inch thick is not even remotely as strong as that sheet rolled into a tube or formed into a box.

In the second and probably final incarnation of my box beam brace, I have developed a set of transfer screws that screw into the holes of my vehicle. These transfer screws and my "trade secret" technique allows me to make and exact template for drilling the mounting holes for my box beam brace.