The affect of the microwave would fall off exponentially with distance. So like if it has X power at Y feet away, and you go out to 2Y feet away, the affect would be quartered. The affect on a drone isn’t going to do much, even if it really messes with your wifi close up.
Out in NYC, the bodegas all have a little plaquard saying that either 1: listed prices include a 2% credit card fee and you can save by using cash, or 2: listed prices may not match your final charge because they add a 2% fee on top for credit cards.
Which is the same thing effectively but it can be sometimes confusing if you’re trying to watch for the fee.
Anecdotally, I have sometimes noticed the cashier will say a price, and then say a slightly different price when I pull out the card. So it’s not like they always apply the fee regardless. At least some of the time anyway.
Not universal of course. I don’t remember if that’s also true for grocery stores, and it’s probably not the case for big chains but honestly I don’t know.