I found a local shop that makes custom motorcycle seats. Same principle. I did not spend much time measuring with him, just told him, or rather, showed him how high and we talked about foam. He had some neat stuff from Germany that is comfortable without being too thick. Mine is only about an inch and a half lower than OEM. Being taller, I was looking for leg room.
I also cut about 2 inches from the two arms that go from the butt bumper or backrest into the seat proper. That allowed the butt bumper to go back a couple more inches. Then the handlebars changed my position to more like a cruiser.
I like what Sissy Mary wrote, something like, riding the Xciting 500 like a Gold Wing.
I have also added some PIAA running lights, mounted down low on the sides of the front fender. Nice at night and on the highway, very visible.