Surpreme Grandmaster
Thanks bro, you know how America has its own signature differentiations in catalogues and Numista, I wish Hong Kong had that, so I can write down and collect all the signature varieties.
As you are based in HK, I would suggest that you either contact the bank HQ in person or via email to see if they can assist you with your inquiry. Each bank has a team that handles public inquiries and they should be able to find that out for you (if they want to). It may not be overnight, as this may take some time. I did my research for the signatures of Guernsey (WC Bull; MJ Brown) and for the latest signatures for those current French Pacific Territories) this way too. The other option is to look for the bank annual reports as they should have names mentioned there with their respective titles too.
I also understand that you can get the HK banknotes catalogue in HK too. Perhaps they have the info there you are looking for. If you need help, perhaps get in touch with your local dealers and they should be able to assist.
Good luck