This study tests whether the BOSS DR12 LOWZ South BAO monopole exhibits the log-periodic β-modes predicted by Unified Substrate Theory. Residuals from two baseline models are analysed at the fixed frequencies β = 4, 9, 16, and 27.57 and calibrated against Gaussian-noise Monte Carlo realizations. No positive β-signal is found; instead, the residuals are unusually β-silent relative to the adopted null model, providing a null consistency test of the framework.