A/C Register Repair Escutcheon?

Our house was remodeled before we bought the place, and frankly, the sheetrock work is not that good. The area around one of the a/c registers is cracking and crumbling. I would like to put an escutcheon or plate between the register and sheetrock to hide the cracking. Is there such a thing? I think it would only need to be 2” or less on each side. Or is this my million dollar idea?