The problem is that they are still boarding basic economy last, and those people are likely to be in middle seats. So people who boarded aisle seats ahead of th

The problem is that they are still boarding basic economy last, and those people are likely to be in middle seats. So people who boarded aisle seats ahead of them will have to get up and block the aisle to let them in. If they found a way to board the middle seats from back to front, that would make things better, but there's no way to order folks like that within a single group.