I'm sure the answer given by Morgan will be that the elongation enables it to move. However you adjust the shims so that the blade can move so from that point of view it's getting to be an iffy answer.
And, I'm pretty sure the spring will wear a groove in it, and once that has happened, I'd have thought it was unlikely to move position.
Sure it's a bodge, but it's cheap, simple and works so I'm not going to worry
