Originally Posted by kawaii

This isn't an issue with the US-issed ABTC (which is the one I have) so I can't say for the HK-issued ABTC. I've never had an immigration agent give me any problems because I've indicated on the immigration form that I was arriving for holiday but still using my ABTC, so I don't think there's necessarily an explicit expectation that you must be on a business visa to use an ABTC.