Well, I guess it would just depend on whether this is going to be something that’s just going to be on display or it’s actually going to be used and washed. If it’s just going to hang on a wall, then you probably have a lot more leeway. People have made t-shirt quilts before so it’s not out of the question, but I’m pretty sure you’ll have to use a knit stabilizer with it or the fabric can get frustrating to sew with. I do love your idea of perhaps just using the fabric for applique. That’s very creative! And the fusible webbing should keep stretchy fabrics in check. I would be careful with the polyester as it can’t handle too high a heat so I would practice to make sure you can fuse it with the webbing and it seems ok. I’d love to see a picture when you finish! 🙂