Corollary to Matter Isoradiality: Astrometric Error Analysis and Extension of Geometric Convergence to the Virgo Supercluster in the TBU Framework

As a direct corollary to the Matter Isoradiality proof within the Time Bubble Universe (TBU) framework, this paper addresses the error budget and astrometric tolerances associated with invariant radius R_0 ≈ 1,044.5 kpc. By incorporating observational uncertainties (parallax errors, distance moduli, and peculiar velocities), we perform an error propagation analysis on the cosmic divergence angle θ. Furthermore, we extend the geometric verification matrix to systems within the Virgo Supercluster (including M87, M104 Sombrero, and NGC 4536 up to ~16.5 Mpc). The results demonstrate that the invariant spherical hypersurface condition holds robustly within instrumental error limits, reinforcing the falsifiable predictive power of the TBU theory on cosmological scales.