GCFT-0684-R0: Radial Propagation, Detector Transfer Functions, and Cross-Instrument Invariance in Gravitational-Wave Tests of GCFT

This paper separates gravitational-wave propagation from detector response in tests of General Coherence Field Theory (GCFT). It distinguishes radiative strain, flux, shell-density proxies, and geometric spreading, and shows why their radial exponents cannot be identified without a derived conservation law. A direct-strain inverse-square law is disfavored as a simple global continuous propagation model. Executed oscillator calculations demonstrate that identical incoming strain can produce substantially different raw detector motion through known transfer functions. A valid cross-instrument GCFT test therefore requires calibrated strain recovery and an independently derived medium coupling; no such GCFT coupling or radial exponent is established here.