Again - read the instructions.
The package of Quilter's Dream (purchased maybe 6 or 7 years ago) had the instructions to NOT WASH in small print on the back of the label.
I don't quite know how to interpret a statement like "5% shrinkage", but I think
I suppose one interpretation would be - if I had something that measured 40 x 60 inches = 2400 square inches
it could shrink to 2280 square inches - a loss of 120 square inches - and usually the package doesn't indicate if that's overall, lengthwise, or crosswise
So if the shrinkage was only one way - you could lose three inches off the length, or two inches off the width, or a less noticeable overall loss if the shrinkage was both lengthwise and crosswise.
So if it went to maximum shrinkage, and the shrinkage was only one way, I could now have an item that measured
40 x 57 or 38 x 60.
That is the extreme case scenario.
Guess that could explain the crinkles - - - - - but if it crinkled, the overall quilt is now smaller.