Cosmological Boundary Guidance and the Galactic Acceleration Scale

A Maxwell-type one-form substrate admits homogeneous background configurations whose boundary scale may be matched to the observed cosmological redshift scale. In a Randers-type guidance geometry, the same background enters the geodesic-deviation sector and produces a characteristic acceleration asub = cH0, numerically of the MOND scale. The result does not derive the boundary value b0, nor does it fix the microscopic potential depth Λ or electromagnetic coupling α. It shows instead that, conditional on a cosmological substrate boundary condition, the galactic acceleration scale is not an independent parameter but a geometric consequence of the guidance sector. Candidate normalizations based on indicatrix-volume and transverse-stiffness arguments are documented as open problems; the electromagnetic coupling sector is treated as an unresolved microscopic frontier.