Has anyone ever finished a product called "Magnum Board"? Its feels like sheets of cement but much smoother than durock. We installed it in this beach house and we might take on the job of finishing it as well if we feel up to. It seems like it would be easier to finish as theres no paper to ruin like on drywall. I did some research from there website and it seems pretty straight forward. Any suggestions would be helpful thanks in advance.