I don't think there would be a problem with it, you know what's in it, just don't iron that piece on high heat after.
When i made my first quilt last year, before I joined this board I knew nothing about fabric selection or anything, so I have poly cotton poplin, 100% cotton quilting fabric, crafter's quality, batik, textured coton (almost like a weave or small waffle) and satin in there, plus a flanelette backing. The woven one shrank more than the others, because I didn't pre-wash, and the satin is more puffy because there was no shrinkage, but my quilt has character. I've also used it a lot and washed it over and over and had no problems.
On another note, my mother and I bought fabric to make a specific quilt, I found my colours in the cottons, and she could only find the right shade of green to go with hers in the broadcloth, 60/40. All she did was make sure to pre-wash everything, and it turned out fine.
All that to say, I don't have a problem using blends in my quilts. :)