Rear frame rail repair need opinion.

[69x22]

I have made up the templates to repair and strengthen my rear frame rails. I will be using the same metal thickness that the G-bar cradle is made out of. Plans are to weld the outer perimeters of the boxing plates and also drill holes in the plates for plug welds. If you look at the templates you will see that they tie into the floor pans and part of the trunk pan on the pinion side of the differential. There will also be a plate on both sides of the pinion tying the front tube of the cradle to both the trunk and floor pans. What do you guys think of this?
The cracks are small and hard to capture with a camera.