I wasn't trying to be arguementative, but just trying to point out some useful info for anyone interested. I've been building trailers on and off since 1975. I have used many axles of both rubber torsion and leaf spring type, and they each have their advantages.
The issue that I was trying to point out it that both axle types should have the bow in them(years ago I made my own axles). The rubber torsion axles are ONLY to be attached to where the bolt holes are. I prefer welding them on, but I only weld them where the bolt holes are and outward. Welding them (even with a reinforcing plate) around the center of the mount restricts the ability for the axle mount to flex as the axle is loaded with weight. Unless someone has an axle that defies the laws of physics, they will all flex.