All I know is that it drives me nuts! I wish they would make a "scant 1/4" foot but I also realize there are other factors involved like where ones needle is positioned and each machines idoscincries. I use a small stack of post-it-notes as a sewing guide and position it after I put my ruler under the needle then line up the notes against it. I have to make sure I use the same ruler each time or it can be off.
Wendy