Although the camera doesn’t hit anything, it seemed entirely too exposed out in front:
So I moved it to the back, where I can’t see it and maybe won’t clobber it:
The camera sensor is now almost exactly aligned with the XY axes, so the goofy rotation is gone and the offsets look better:
The size of the “10 mm” inner circle at the crosshair depends on the target distance, so it’ll be smaller for surfaces clamped onto and thus rising above the table. Depending on how much that matters, I can tweak the camera focus and scale factor to make the answer come out right.
The setup at the home position looked like this from a different perspective:
No operational change, just a cleanup.