These are all good things to think about. I noticed the same thing when I used antique embroidered squares to make the centers for modern log cabins. The quilting was a rather large meander and the batting was poly. The dang thing was as stiff as a board. I couldn't wash it because it was a gift for a dying friend and there was no time to try and experiment with softening it. I've not forgotten that experience and been fearful of having it happen again. I do think a small cool wash might have made a difference but, as I say...no time and if the embroidered blocks had bled or whatever, it would have been a catastrophe.