Been there, done that. If you have enough fabric, the best solution would be to take off the edge triangles and put new ones on that are big enough to include the seam allowance. Having learned my lesson once, I now cut my setting and corner triangles about 1/2" big and then trim them to leave that essential 1/4" so the block points don't get cit off. My theory is: if you haven't done this, you haven't designed enough on point quilts yourself. It's part of the learning process.