Originally Posted by FBinNY

Overall that's all true, but not necessarily convenient. With respect to SB who's not here to debate this, 3.5mm per side is quite acceptable in most cases. But 1mm per side, while OK in a pinch, can make wheel position issues because the ends are chamfered either by design or wear. That means you'll be mounting to a sloping target and you'll lose the reliability of automatic wheel position by gravity.