That width and height is the size of the skeleton in the setup pose in Spine. You can use that to decide how much you want to scale your skeleton (either by setting the skeleton scale (in 3.7 runtimes), setting the root bone scale, or setting the scale on the SkeletonJson or SkeletanBinary loader). Eg, if you setup pose is 300 and you want the skeleton to be 600, then set the scale to 2.
