Well, we don't know how small are the objects that the OP is going to photograph. I certainly agree that, if they all are spherical, there is no point in rotating the focus plane. One assumes a photographer does not only take pictures of exactly spherical objects, and if they are not all exactly spherical (watches, jewels, who knows) a rotation in focal plane might give a substantial help for the final image quality (let's say aligning the focus plane with the dial - thickness of the watch). But I never used a bellows with movements, althought I've read it helps, I would be glad to be able to give an answer validated by experience.

IIRC there was a Kenko bellows in the eighties (for 35mm) that had movements in both standards.