I have a ultra-short throw projector with your CLR/CLR 2/CLR 3 fixed frame screen and I see that the projector doesn't fill the screen completely with the screen totally flat.  One side edge appears to not fill correctly. I also really hate the halo of reflected light that surrounds the screen.In our experience it has to do also with the flatness of the wall.  Not all walls are completely flat and the uneven side can cause the screen to pop out/stick out on the corner and not allow the projector to properly fill out the edges. Projector manufacturers usually have small legs at the bottom that allow the projector to adjust the projection image to offset this. The halo effect is possibly normal but some projector manufacturers have a masking option in their menu to eliminate light bleed outside the area.