As stated in my previous post, HKCAD is a very conservative organisation. If they are telling you what they require, then unfortunately I do not see much scope for you to find a way around.
HKCAD is not like other larger, less centralised regulatory agencies (eg. FAA) where you might be able to hunt around until you find a FSDO who might interpret things more favourably for you. HKCAD is a small, ordered organisation with established rules and procedures that are zealously followed. Conservatism is their hallmark.
My best advice is to seek a face to face meeting with them, bring along your supporting evidence (paper logbooks!, certificates etc) and discuss your case with them. Sorry I can not suggest a clearer solution. Good luck!