I'll give it a try. (= This is indeed a cool problem.
Comment: If white plays at the middle a, black could also play on one of the side a, making b and the remaining a miai. White has then the same amount of threats, but black has the chance to gain two additional points later if white tenukis.
Some failed attempts:
After , takes away the second eye. Playing at a does not help; black can capture but still does not get a second eye. Playing at b does not help either since white has enough time to escape.
does not work either: after the exchange of and , the throw-in at dashes black's hopes for a second eye.