This paper develops the astrophysical consequences of interface-dominated admissibility in the overlap-growth framework introduced in Paper A. Recent JWST observations reveal compact, luminous, centrally organized systems at high redshift that strain purely hierarchical (LambdaCDM) assembly timelines. Assuming early cosmic evolution is governed by interface-dominated admissibility (as developed in Paper A), we identify the astrophysical signatures that must follow from such a regime. Core consequences:- Accelerated early structure formation relative to gravitational free-fall assembly- Enhanced compactness and statistically preferred early structural scales- Efficient early black hole growth in constrained regimes- Coherence-filtered radiative transfer, including suppressed high-energy channels and luminosity-mass decoupling- Coherence-aligned angular momentum acquisition and enhanced alignment signatures at high redshift- Non-monotonic population statistics with demographic edges and transitional populations- A cosmic evolution picture in which late-time darkness emerges from progressive decoupling rather than energy depletion The framework does not modify global expansion or local conservation laws. Predictions are explicit and falsifiable using existing and near-term observations. Companion framework paper (Paper A):https://zenodo.org/records/18508456