Since Solid Iris was acquired by Altair, many of it's rendering plugins have stopped being developed. I was one of the few who actually bought this plugin, and from communication with them, they ultimately felt there was not enough interest in the plugin to continue immediate development. They did say they would continue to evaluate the interest in the future, and that's why they are leaving the demo available. They are working on a rather big internal upgrade to the rendering engines, so after that they will incorporate it into the various plugins. If you would like to see this get updated for FormZ, please reach out to them and let them know you are interested.