I have done appliqué both ways, and I highly recommend doing the appliqué first. Trying to maneuver any size of quilt through a domestic machine can be challenging. It is much easier to maneuver a flimsy! I try hard to appliqué on blocks before piecing, but there are some things that just don’t work that way. I have done buttonhole, satin, zig zag, and raw edge in various ways. Only raw edge (done in FMQ style, not on a domestic machine) was halfway easy to do after quilting.