...
The limitations of the demo version include limited resolution and a red watermark in the generated HDRI map, and once you create your IBL environment for Fire, it is always converted to a white dome when the scene is launched in Maxwell Render.
By purchasing the full version you will disable these limitations, and be able to create full resolution HDRI maps and store them to disk to be used in your renders.
Check this section to find some videotutorials about how to use HDR Light Studio within Studio.
...