As I wouldn't drink beer if it were free, your assumption is somewhat misplaced.
Yes, there is a charge normally, for exchanging £ to THB, but, as I made clear in my previous post, I don't get charged for the exchange within the App. The only charge is the transfer of those BHT to the Thai Bank, which as stated, is between 45 and 49 THB each time. There is of course, a possibility I get privileged transactions, but if such is the case, I don't remember such an offer being made.
Look up www.Revolut.com