I see that there is some confusion here about cable riggings and composite trees. Everybody does somethings different than everyone else. But here's what I do and do know.
The Double H Cable Rigging™ has two ways that the latigo is locked into place. One: the 1/4" lock collar that goes in a wear leather under the latigo. This is not much smaller than any piece of leather that normal rigging are made of and the latigo would have to go around. Two: a billet system that creates a compound curve in the cable using an adjustable strap of nylon webbing and a buckle that acts as a backer to the latigo. Both systems limit bulk under the jockey's and legs.
I make a urethane saddle tree. Sure it's molded, but I made those molds by hand. I know the shapes work. I make the materials too, like a cook with a very accurate recipe. And when the saddle trees come out of the molds; I shape those to the all possible shapes for all horses and their backs, BY HAND. The bars are a standard 22". How much longer do they need to be? The material is strong. Used for ballistics shields. If it couldn't take a bullet and keep it, I don't use it. That means the screws, nails and tacks, stay. And they'll stay forever. They won't walk out like the nails in older saddle trees.
Hamley made the cable rigging back in 1918 and used it till 1924. The cable was wire an inch thick, of braided wire that would rust. Fencing wire basically. The technology wasn't up to the task. It took the industry this long to see a great idea come back. It was a good idea then. Now, it's just better. They weren't the only ones to use it either. Go to the King's Saddlery in Sheridan WY. Go upstairs in the back of the room this year, ( since they rotate their collection) there were two other companies saddles there that had cable rigging. From the same years.