The HK card with USD balance can actually be added to Apple Pay and can therefore be used in normal stores as well. If the payment is in any other currency then USD, it will be auto converted.
What about Google pay?
For those who are in the EU, such cards do not really have much use - because, first of all, they do not support adding to mobile wallets, and they also do not support 3DS - which means that their use is very limited. On the other hand, those who buy online where no additional verification is required could perhaps benefit from this kind of service.
But you will not be able to pay with the plastic card in stores? As far as I know it is not mandatory to add them to your cell phone. It is even better for your privacy that neither Apple nor Google know about this card. Or withdraw money at ATMs?
I do see potential in this, in the absence of further clarification, and I don't see the rates as far-fetched.
I wouldn't buy them now but later in the year I will probably be interested.
Thanks for the feedback and you're welcome to try them out anytime you like.
To answer your questions:
There is no physical plastic card.
For now only Apple Pay is supported but google pay should be added in the future somewhere.
And if you want Apple to know or not is completely up to you, as long as you have nothing to hide there shouldn't be any issues
Unless you're trying to avoid paying taxes while spending your crypto on different fictitious names all should be fine haha.