I haven't had the forked pins very long, but haven't had any bend. They kind of squish together where the opening between the forks gets smaller, but as you put them in the fabric you just spread them as wide as you'd like.
My husband also brought home an old school carpenter's ruler which is 6' long, but folds in sections. Remember those? Some of my quilts are longer than 6' diagonally though so the aluminum thingy works great. I think you could put it behind a door, but I have different sized cutting mats, etc stored behind this cabinet and it fits right in there with those.