Thanks. I remember percysmith had an issue with Harrods a number of years ago, but I think they've fixed their implementation. I haven't purchased anything from the Knightsbridge location since before I had contactless cards and mobile payment options. The airport location disallowed a mobile payment about to years ago saying it exceeded the limit.

The VAT refund process is a scam and has been talked about here for lack of a better thread. I scoured the options with Global Blue, and there weren't any good solutions. Even getting a cash refund in local currency had a fee. The only way would be getting a refund to a Visa/MC that has a native currency of the country in which the refund was processed. However, since EU country residents are ineligible for the refunds, I don't know how common it would be where one would have a Euro denominated card if not a resident.