My CRD plate "rear tongue lip" broke after some enduro cross practice.
It never rattled, though. I also put six dollops of silicone around the front, sides, and rear. I squirt the dollops and (with the plate off) let the silicone get semi-cured over night. Then I put the plate on tight and let it cure some more.
I did the same to my new (and waaaaay over-priced) Frenchie skid plate. "Mech"-something. The front mounting bracket is just stamped steel so it will flex out of shape and cause the whole unit to rattle like crazy.
My fix was to weld a small gusset spanned across the back of the clamp to keep the lips of the clamp from bending inward. So far, with the weld and the silicone, no problems.
F_G has a different skid plate on his. Perhaps he'll chime in.