I have this foot and the plate has a smaller hole for straight stiching...you just have to be careful that you remember to change the plate when you are using the other stitches...(speaking from experience...broken needles)
But I have to say about this Accufeed 1/4 inch foot that I have returned to using the regular 1/4 inch foot that came with the machine...it was just working better for me...I am getting a straighter stitch line, and a more accurate seam...I have kept the straight stitch plate...
I wonder if anyone else has had this experience with the Accufeed foot.