We construct the multi-messenger observational synthesis of the finite-capacity latency–erasure theory by unifying its detector-facing predictions across stellar-mass compact-binary mergers, massive black-hole inspirals and mergers, pulsar timing array backgrounds, and cosmic microwave background tensor observables. Earlier FCLET analyses established the theoretical architecture of the program from finite-capacity microstate structure and emergent latency to cosmological freeze-out, compact-object shell formation, Kerr strong-field phenomenology, and direct confrontation with gravitational-wave data. What remained open was the global observational synthesis: how the same micro-capacity law projects into all major gravitational and cosmological measurement windows over the next observational era. The present article establishes that synthesis in full. The central claim is exact. LVK, LISA, PTA, and CMB are not independent external tests attached to separate FCLET submodels. They are frequency-separated and regime-separated measurement windows on the same underlying law. The burden fraction , the latency response , and the overwrite or closure sector determine cosmological freeze-out at the largest scales, relic stochastic structure at nanohertz frequencies, massive compact-object shell phenomenology in the millihertz band, and detector-facing post-merger shell signatures in the audio band. The observational program of FCLET is therefore not a collection of unrelated forecasts. It is one hierarchical transport-and-saturation atlas spanning cosmic history. A unified messenger map is derived in which each window is associated with a distinct saturation regime, observable hierarchy, and sensitivity functional. The CMB probes the largest-scale primordial tensor suppression and saturation consistency relations. PTA observables probe the low-frequency relic tensor background and transfer-modified stochastic structure. LISA probes long-baseline strong-field transport, supermassive shell phenomenology, and the mass-scaled shell-response regime. LVK probes the highest-curvature stellar-mass post-merger shell signatures and immediate detector-level confrontation against Kerr-family alternatives. The theory is then represented by a single global parameter manifold, projected into messenger-specific observable spaces and combined into a unified survival and falsification geometry. Five main results are established. First, a messenger-unified observable dictionary is constructed from the FCLET microstate law. Second, window-specific sensitivity directions and degeneracy structures are identified for LVK, LISA, PTA, and CMB. Third, a cross-window consistency system is derived, showing how a theory point that survives one window constrains what must appear in the others. Fourth, a global weighted synthesis framework is built to combine current and future observations into a single survival map. Fifth, decisive falsification routes are identified, showing exactly how the next generation of multi-band gravitational and cosmological measurements can either preserve or eliminate the remaining theory corridor. The result is not an auxiliary outlook paper appended to a completed sequence. It is the final observational constitution of the finite-capacity latency–erasure program.
Ali Caner Yücel (Fri,) studied this question.