For machine applique on my Bernina 1230, I use a blind hem stitch rather than a blanket stitch. I use an open toe embroidery foot for the blind hem stitch.
I think on a lot of machines the blanket stitch has one of those triple stitches in it to make it thicker. That is great if you are doing the old-fashioned black blanket stitch.
Mostly what I am doing is invisible machine applique; the blind hem stitch is a better choice for that because it is more adjustable and less visible.