Galaxies at z of 7 to 8 hold dust reservoirs of 10⁷ solar masses (A1689-zD1; REBELS) when AGB factories have not yet opened and supernova arithmetic falls short: net yields of hundredths of a solar mass per event, after reverse-shock destruction, cannot build the reservoirs within the integrated supernova count ΛCDM's throttled early star formation permits. Every gram of dust doubles as fast-enrichment evidence, compounding the chemical-maturity timeline problem.
The dust clock starts with the first stars near z of 20 to 25 and runs through hierarchical assembly: the supernova count available to any early galaxy is capped by halo growth. With the factories capped and yields measured small, observed reservoirs force tuning at every stage: maximal yields, suppressed destruction, accelerated grain growth, invoked jointly and exactly where they cannot be independently calibrated.
SCT decompresses the dust timeline the same way it decompresses the oxygen: collision-seeded proto-structures begin star formation at deposition (P56, P22), so a z of 7 galaxy carries more completed stellar generations, hence more integrated supernovae and even early AGB contributions, than the hierarchical clock allows. The reservoir arithmetic closes with standard yields and standard destruction: the budget crisis was a factory-count deficit, not grain physics, and it is the identical head start that supplies the tenth-solar oxygen at z of 14 (P25 supplying the dense early reservoirs that accelerate ISM grain growth as the secondary modulation).
The dust-to-gas systematics ride the same structure: deposition-fed systems carry baseline-diluted gas alongside locally enriched pockets (the reservoir arithmetic of the He-3 and deuterium entries), so high-redshift systems scatter off the local metallicity relation in both directions, exactly as observed, while the local relation's tuned accretion-destruction balance reflects inflow architecture rather than knife-edge grain physics. Dust censuses become chronology probes: reservoir masses versus epoch measure the seeding head start directly.
This is the same early-generations physics behind the z of 14 chemistry and the quenched-galaxy timing. There is no need to switch off reverse shocks or run grain growth beyond its low-metallicity physics.
The chronology is the test: SCT requires dust reservoirs to extend as early as seeded systems do, scaling with the head start; JWST and ALMA finding a sharp dust floor, reservoirs collapsing to the standard supernova arithmetic at all z above 10 with budgets closing under the hierarchical clock, would remove the factory-count deficit and the head start with it. The registered demographic kills apply upstream: no massive seeded systems at z above 14 collapses the population whose generations build the dust.