one last thought ...i started spray basting my flannel & minky quilts several years ago. was amazed at how stable all was. both minky & flannel stretch quite a bit & regardless of how densely i basted. i got tucks & creases in the back. especially at seam intersections. first attempt w spray basting i was amazed ..& i only spray baste these types of quilts now. i don't know if you have a long arm or use a domestic, i use a domestic ..janome 1600 ..even the weight & size of medium large minky quilt works on my machine. i have a friend that puts minky on backs of most the quilts she makes for friends or her grands. has long arm ..says using long arm on minky is difficult because of stretching. so ..if you long arm, perhaps you could get some input from longarmers here on the board who have experince w minky quilts & have tips/tricks to help you. may need to start a new discussion thread for this subject.
..looking forward to seeing pics of this quilt finished!!!