Quite possible, but when I checked it was something like 0.5%, more than an order of magnitude better than the "convenience" of having a chinese bank bill your card in USD.

I asked them (my bank) about it, got a response I don't remember, and decided I could live with 0.5%

There are several cards available in Britain which use the VISA/MasterCard spot rate, and add no further fees.

The cards tend to have no other promotion, whereas comparable cards might include travel insurance, or some gift vouchers when you sign up.