I have 2 of the foam insulation boards. When I'm not working on something big, I put one behind the other and they stand nicely against the wall. When I'm working on a big quilt, I close the closet door and stand them side by side so I can lay out the whole thing. I don't have them fastened to the wall. I felt that would limit their usefulness. Now I can move them wherever I want them.
I never used the gridded flannel. I figured that would be too hard to me to get straight on the boards and I probably wouldn't use it that much anyway.