GiftCards.com has been one of my favorite ways to meet minimum spend on my credit card due to how easy it is and the low cost if you factor in portal cashback. It looks like there has been a recent change to charge a $4.75 fee if your billing and shipping addresses are different, if you select USPS Priority Mail or above as your shipping option.
I tend to have different shipping and billing addresses as I rent but my parents live nearby. I don’t like giving my rental address as my billing address, and I don’t know when I will move, but I know my parents will be still at their address and not too far away.