dolpinsky
Despite that overseas interview is still an option on the application, I think it will better your chances if you show your sincerity by getting yourself back to Hong Kong.
I met another guy that flew all the way here from New Zealand during my stage 1, he said the odds of an overseas interview is getting quite dim, considering they now only accept PERMANENT HKID holders.
EDIT: Correct me if I am wrong: You buy your own ticket and pay for your accommodation, the only perk is you get to live in their hotel during the FEW days you are there for both stage 1 AND 2. It is a crammed schedule if you are an overseas applicant.