IV.P220 — HL-LHC and FCC-hh Falsification Window

τ-SM gap only +16 ppm (0.0016%). HL-LHC 50%, ILC 27%, FCC-hh 3-5% precision on λ_H: none can discriminate τ from SM via HH production. Frameworks experimentally degenerate in quartic coupling. Compositeness signatures (form factors, resonances) remain primary discriminant.