4.5 means your listening capability is still with difficulty. It is maybe risk and little chance for you to get a waiver. I suggest you should make a good preparation for your next interview in Honkong or Beijing now.
A friend of mine (IELTS:L7R4.5W6S6) had been informed to take a interview in Hongkong. It is really a pity for him. But it is lucky to him that he has passed the interview and received the landing paper now.