Can't offer much help -- I can say that my friend loaded a minky back for a baby quilt and, well life got in the way. After a couple of weeks the fabric was much stretched out and sagged significantly.
I ended up doing the baby quilts (twins even!) for her. I was able to use the stretched out back so they would match by turning it the other direction. Don't really remember any thing eventful or dreadfully different about the actual quilting but I think we had to raise the foot thing up a bit.