I don't have much more to share, except that I think what seems like a big deal will get much less important in the context of a big quilt. Also, that piece shows the seams as you're holding it up in the air, however, I wonder if they would show after it's placed on the quilt with quilt top, batting and backing behind it. But stuffing it with a little thin batting would be cute, so go for it!
If doing so gets too hard, I'd definitely see if the seams will disappear with the other layers behind it.