I would NOT choose a Bitcoin option unless the shop had been negotiated for fee and reimbursement in Bitcoin when I originally agreed to it and my required purchases were being paid for in Bitcoin.. My contracted fee was agreed to in the official currency of my country. I would not accept my $25 as $25 'worth' of corn, soybeans, apples, potting soil or other commodities. Even when I do a 'reimbursement only' shop, the value of the commodities I purchase is negotiated in the official currency of my country as that is the currency I will be spending. My country's official currency is a commodity itself and fluctuates in value day to day as well as losing value over time due to inflation. Adding a second tier of fluctuation by being paid/reimbursed in a different commodity just adds more volatility.
If I subsequently decide to purchase some commodity with my reimbursement or fee--such as Bitcoin, sneakers, shares of stock or a can of soda--that decision is mine as to the item, the timing and the acceptable purchase price. I neither want nor need for someone else to make those decisions for me.