I did minky on the back of baby quilts and didn't have any problems. I do have a mid arm machine, and the top
was pieced in 100% cotton fabrics. I did use batting because I wanted it softer. I think the thing that probably
made yours difficult, is if you sewed 2 pieces of minky together. I think that stretch would be real hard to do well.
What if you sewed the Minky to a stabilizer? I think I will probably not sew Minky to Minky.