Cutting back is pretty much universal for pines.
JBP are really strong growers, and needle pulling helps slow them down. Again, it’s primarily a refinement thing.
The key thing with pines is to retain foliage close to the trunk. As the branches grow, the foliage will get farther and farther away from the trunk, and the tree will become “hollow”, that is, there’s an outer perimeter of green foliage and an empty void inside.
To keep this from happening, the branches need to be developed into pads, with interior branchlets that can still get some sun exposure. And as the primary branch grows out too long, it gets cut back, and one of the branchlets gets positioned to take its place. All the while developing even more interior branches for the future.
This is really the heart and soul of bonsai. Continuing refinement and development to maintain the tree for decades.
