Analysis:
The rule does not apply.
The rule for avoiding a blockage does not apply to our hearts, because we will only ever make two tricks in the suit. Instead, we should check whether we need to preserve one of our heart honours as an entry. And we do! We need five club tricks, and that suit is blocked from the beginning. We must unblock it and then return to the long hand with ♥A. So we must win the first trick with the ♥K in hand.
The blockage we create by winning the first trick with the ♥K is irrelevant.
