I just took a bicentennial 1976 quilt out of the closet for a look recently. It was made by my MIL and has a poly batt which is bearding in many, many places. I wonder if the newer poly batts beard. You also never want to touch an iron to the quilt with poly batting as it becomes flat. I found out the hard way when pressing the binding over the edge of the quilt.
I prefer wool batting for loft and the trapunto look without the work of trapunto. It doesn't melt!
The 1976 quilt was hand quilted, and now has many broken stitches. We used this quilt for probably 15 years, and I never noticed what had happened to the thread. It is so sad to see this after so much work was put into this quilt.