I suggest you check out the Youtube video, "You can quilt that out". I am a novice long arm quilter, and I would suggest that if you expect the best from the long arm quilter, then you should give the long arm quilter the best you can do. We are not magicians. If you measure your quilt away from the edge of the top and cut both sides the same identical length, and then pin pin pin, you shouldn't have wavy borders. I always pin the ends first and then work from the center out. My mother used to say "Any job worth doing is worth doing well". Don't assume someone else will be able to cover your mistakes.