I'd love to see a tute on your mitering method.
Can't have too many binding tutes !
That is not how I do it. I miter that corner by turning it inside out and machine stitch, cut the triangle point off, turn it out and press with the seam open and then stitch it down, no opening in the corner. If need be I will try a tutorial on it. It is really very easy, once you have tried it.