That little wedge is there even with traditional binding technique. And if you're like me and don't sew in the corner at all, you don't even have to pull out the stitches.
So my technique:
1. Sew to seam allowance's <seam allowance=""> distance from the end of a side.
2. Pull the quilt out, fold binding 45 degrees, fold down.
3. Start sewing new side at <seam allowance=""> seam allowance's distance from the edge of the previous side.
4. Finish all.
5. Clip off wedgie, per Patrick.
Gonna experiment with clipping before I try it on a "real" quilt.</seam></seam>