Yep, I do all my own profiles. Your grainyness may be cause by a bad reading on you transition from your Light Magenta to Magenta and Light Cyan to Cyan. Make sure you ink restrictions are nice curves and not jaggedy otherwise it could cause that. Also, when I had UV Premium inks from AGFA their Light Cyan was way dark which caused my light color areas to appear more grainy because the color was wrong. When I switched to HC Ink I had better results.