@Ploshkin I asked Imi the same question but face to face so it was easier to point and gesture. If you want it filled with wadding while not losing any of your work so far, the only way, I believe, is to add some extra wadding around the edge which might be a problem. You would have needed to anticipate this eventuality and cut the wadding that much bigger than the patchwork bit.
It was for my one and only so far quilt which was the qayg BOM from 2020. However, I'm very happy with the narrow binding and the flange, as it goes.