There have been several reported incidents of ripping the threads off the end of the curl ram, or breaking it, or in at least one case, shattering the piston. This style FEL has only one curl ram, instead of the two most loaders have, therefore all of the force from back dragging is placed on one ram, instead of being shared by two.
In most cases I have heard of, the bucket encountered deep seated rocks, tree roots, or stumps. I think if you use common sense & are just spreading material, or grading soft ground without the aforementioned obstacles, you will be fine.
Just be aware of the possibility of damage.