No! I don't clip curves when quilting. The seam allowance is so small. This isn't like sewing and having a bigger seam allowance. This is for piecing. I do clip for applique applications as needed ... but, I don't do hand applique anymore. I do fusible applique and then finish the edge with a wobble stitch or something like that.
My different curved quilts have all been flat ... no puckers or anything.
I would have to be a really extreme curve before I'd even consider clipping a seam.
ali