Correct - that is the difference, I'm going past the meridian. Now that you mention it, I remember my focuser used to graze the top of the 10 micron housing if I had it at an angle. A had to use standoffs between the refractor and the lozmandy.
I don't have the same issue with the Paramount MX but sometimes use a 0.5" standoff under short refractors tube rings as they have to be positioned well-forward and the focuser / camera fouls (any) Lozmandy clamp.