It's called fair use. You can use the figure in the way you intend. But it
can't hurt to contact LucasFilm. Who knows? You might open up
communication with someone there.

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The aim of an argument or discussion should not be victory, but progress.
Joseph Joubert, essayist (1754-1824)

And if anything, you could shoot the shot as a close-up of the foot stepping on the toy making it a very easy shot to reshoot if necessary, since all you would be shooting would be a foot which wouldn't even necessarily need to be the actor playing the part of the character stepping on it.