One thing to check is your boyfriend's plans and whether he can add you to his company plan as I do with my common-law wife who is still in Canada.
The irony for me is that of my two brothers and one sister, I am the only one that did not officially get a marriage licence and I am the only one of them other than my parents not to be divorced. The Canadian government is not hung up on licences and we file joint tax returns and she is on my health and extended health and dental plans.
In applying for a Visa for HK for me only, the last 30 years for them with my wife are totally irrelevant. Very strange and old fashioned thinking.
In Canada, it has been a long standing principle of law that even if you moved in with a woman who had a child from an earlier marriage, the partner would become by virtue of 'in loco parentis' an acknowledged legal parent. In fact, my friend got into that arrangement and left the c/l arrangement after a couple of rocky years. The woman was angry and took him to court to pay child support for the child that was not his. She won. Later he met the judge while jogging one day and asked him how that could happen when that woman never made the legal father pay one cent while she kept taking him back to court for more every time he heard he got a promotion and ergo more salary. The judge just said that was the law!!!
I know this as one day while walking to a meeting together we ran into a mutual friend of ours that my buddy had played pro football with. He asked what the two of us were doing together as he didn't know the guy took a good management job at my firm. I blurted it all out. As we walked away, my pal said that was bad as his ex gf was that guy's cousin! That led him to the ill-fated court case. Thereafter she found a way to find out how he was doing and would have him back to court when he was promoted or got a pay increase. Clearly someone else leaked that information as it became regular in the years of big pay increases and bonuses!!!