3ds Max :: How To Use Cubemap For Reflections When Using Scanline Renderer

I understand that cubemaps are primarily used in realtime applications, like game engines, but is there a way to use a cubemap for reflections when using the scanline renderer? I loaded a cube map into the environment map slot, but you can see the black areas around the cross of the cube map in the reflections.

I also tried making a big inverted cube, and mapping the cube map to that. It sort of works, but the reflections aren't nearly as vivid as they were when I used the map as the environment. I disable cast & receive shadows on the cube. Not sure what the best way to go about this is.