Lorentz Invariance of the Zero-Point Emergent Gravity Vacuum

the continuum limit of Spectral Exclusion remains consistent with local Lorentz invariance but does not derive an exact invariant speed from mode restriction. Standard laboratory tests of the speed of light bound possible residuals but they do not prove that any residual vanishes identically. A non-fitted estimate of the laboratory-relevant gravitational-wave contribution lies below current optical-cavity bounds and is therefore allowed. A new minimal relation is introduced that quantifies residual geodesic stretch from restriction inhomogeneity together with the gravitational-wave background. Complete trapping at spectral boundaries is distinguished from this mild bulk effect.