Originally Posted by diredesire
I don't actually see the POINT of it either, but the 2 point mount on my 5800 ELS has the markings, too. I am pretty sure the mounts are symmetrical about the center of the turn table, the only reason I can imagine is that often times the throat of the frame is thinner than the tip of the frame, so the adjustable mounting posts (white) need to be adjusted less frequently if you've got one side always at one end (and don't have to look for it). Otherwise...
I should note that it'd be really nice if we could offset the mounting stocks, I like mounting my frames slightly lower (with the frame offset towards the handle side a little bit). I find that this is much easier on the Prince O3 frames.
You make a good point. I have a strip of leather grip on the throat side, for thinner beam rackets. On the 6-point mounts, you can off set the racket from center with the billards.