I ordered my Brompton back before COVID appeared. Which is why I ordered a big Brompton bag for touring. I didn't bother with getting a smaller bag. My plans were all about travel.
One of the great points about a Brompton is the luggage system. There's a luggage carrier block on the frame. Brompton has a large range of bags of all sizes and uses. Each bag has a sturdy piece that clips onto the carrier block. It doesn't move with the handlebars. That means the weight of the bag and its contents doesn't interfere with steering.
My big touring bag (a large Borough roll top bag) is a bit of overkill for errands and short local rides. The smaller basket bag (the Borough basket bag) is a better choice. So I ordered one in July. Times being what they are, I had to order it from London. I definitely like it. Perfect size. It folds. There's outside webbing for hanging stuff. (Like my little hand sanitizer bottle.) There's an inside organizing pocket for wallet, phone, and keys. It has strap handles that make it easy to carry as a should bag off the bike. Definitely better than my little backpack or a string bag, especially in the humid heat of summer in Miami.
When the basket bag arrived, I clipped it onto the bike for a ride. I couldn't believe I'd gotten along without it. Perfect for quick shopping stops. Perfect for carrying a snack and my little thermos of espresso.
Proof that happiness can be found in the little things in life.