It will result in nothing but trolling in exchange for a pretend benefit. If customers want to know if the exchange rate is good or acceptable, that info should be part of the transaction. Screen shows qr, dash amount, dollar amount, exchange rate. If you don't consent, don't. Same as a cashier showing you the total before you swipe your debit card. You're agreeing to the terms of the transaction as displayed. If you think the rate is bogus, bye bye! Not hard. Not new. Dude, thats what grandma said!