The straight entension arm does not seem to fit perfecting onto the Ozmo, the arm "jiggles" (technical term) up and down about 3/8" even when tightened.  It seems the teeth just are not a perfect match.

Anyone else experiance this?

If that's the case something isn't right.
The arm should lock solid with no movement. It doesn't need to be screwed very tight to lock, the teeth should mesh with no play.
So sounds like something is wrong with one of the plates.

If you find any defect about the accessories, please check with your dealer ASAP.