Hi Flapman,
Yes, I'm referring to 3ds max and that's the process I go through as well. But usually i'm working with a vray mtl light texture making the vray light useless and I Unwrap my Uvw, render to texture my target map slot is usually light color, save and go to photoshop.
However with my skybox I added a standard bitmap texture and unwrap say the floor and render to texture, I get a different set of target map settings and don't really know which one works the best. I've tried ambient color and diffuse but they make the texture really ugly.