PlasticScale emerges within Socioplastics as a functionally invariant infrastructural chassis, displacing mythic sovereignty and mechanical amplification with a minimal yet comprehensive operational core. Its architecture is constituted by ten interdependent functions—field detection, boundary inscription, procedural rule, ordering syntax, filtration, trace registration, adaptive modulation, closure, scalar continuity and internal review—whose coherence derives from relational interdependence rather than hierarchical command. None prescribes ideological content; together they stabilise intervention across heterogeneous contexts. Validation is endogenous: deviations manifest as functional discontinuities detectable within the system’s own recursive sensing, obviating reliance on external benchmarking. Scale, articulated through the PlasticScale Index (PSI = (A ÷ I) × C), becomes a measurable relation between intensity, reach and coherence, yet remains dynamically calibrated rather than reductively quantified. Scalar invariance ensures that the same architecture governs micro textual adjustments and macro governance frameworks without structural distortion; magnitude alters implementation, not chassis. Through MUSE as semantic interface, invariant functions translate into domain-specific consoles while preserving core integrity. PlasticScale constructs itself autophagically: each cycle generates trace, filtered and reintegrated as operative material, sustaining transformation without entropy. Manifested through a distributed anatomy of nodes, slugs and mesh, it replaces sovereign centrality with proportionally governed co-presence. Thus PlasticScale proposes not spectacle but proportional governance—ten functions, one index, three scalar regimes—deployable anywhere scale requires calibration without domination.