So I understand this isn't exactly what you are talking about, but here is how I solved my carbon fork dilemma. SKS Anywhere Mounts. They've got a plastic wedge with a rubber backing that gets velcro'ed to the fork. Technically they are intended for adding a bottle cage to your triangle, but it seemed to work pretty well on the fork. I added a layer of inner tube underneath first to help protect the fork and keep it all from sliding. Just make sure you cinch down that velcro TIGHT.
I have seen similar things like that before. I think 2 fish makes them as well. I just don't know how solid they would be for anything cages. I may want to carry a full 64 ounce growler on one lol!!! Don't laugh. A buddy of mine did that last fall on a gravel trip lol.