[Supraspinatus]

I'm of the opinion that postural alignment comes first, head posture and neck comfort come second, your chosen anchor location comes third, and that the string blur's location is a consequence of the first three. Wherever it ends up, it ends up. It might end up way off to the right if you anchor side of the mouth, and be of no use. It might line up with the riser - great! But personally, I'm going to avoid canting my head, or changing the alignment of my shoulders, to attain a particular alignment of the string in my sight picture.

However, c_m_shooter, above, shoots way better than I do, and is always worth listening to.