Interesting. Considering how much bunching there has to be (arc length of a 16" deep parabola over a span of 52" is 63", has to jam into a 36" width) I would have guessed that grosgrain was too stiff.
Can't get anything by the Grizz. You are right. I did use something else to edge it with. It came on a roll just like the grosgrain I use. I will check to get the exact description next time I am at the big chain sewing store that gear builders don't admit to going to.