I am thinking a quarter inch is a quarter inch and the manufacturers should fix the foot to be what it is supposed to be and the pattern makers should allow for the thread, etc., or more than they are presently. I have a 43-year old Elna Super that does a superb job of sewing. My first project nearly drove me carefully as I was religiously adhering to the 1/4 inch foot. Discovered my putting a tape measure at the edge of the foot and lowering the needle manually that it was off a skosh. Moved the needle and marked it because it isn't off as much as where the markings start. Now the projects are going swimmingly regardless of thread, thickness of fabric, etc. Also measure a lot to be sure it doesn't get off before going too far.