To my reading, OP didn't intend to convey "unpredictable" so much as "large," and if he did, then I'm not sure what he was thinking; "quantum leap" isn't even c

To my reading, OP didn't intend to convey "unpredictable" so much as "large," and if he did, then I'm not sure what he was thinking; "quantum leap" isn't even colloquially understood to mean "unpredictable change".