I started from 3BRBS's design and extended the interior dice ramps to make it easier to print with fewer supports. I was having bed adhesion issues with my printer at the time I printed and I did have a problem with warping at the corner, so I also designed and included a simple base piece that fits snugly around the bottom and conceals the defect on my print. As it turned out, it added a nice detail around the bottom, so you might want to use it too.