😆 I do love that they gave Cora a line where she called Aurora “plucky”, and shortly thereafter, she had her heart plucked.
Anyway, in regards to the technical question, I’m thinking that the plucker can relinquish the power if they willingly give it to someone else. In The Doctor, we saw Rumple pluck the unicorn’s heart, then he handed it over to Regina, telling her to kill it. He gave up the heart, and in doing so, gave Regina control over it. Same deal with Hook giving Aurora’s heart to Cora.