Addendum: Scope Clarification on Momentum Exchange and Finite Stroke Limits in Phase-Gated Inertial Systems

This addendum provides a final scope clarification for the author’s previously published preprints on phase-gated inertial mechanisms. The underlying mathematical models and internal force analyses remain unchanged; this document addresses interpretation and physical limits only. The clarified result is that phase-gated inertial coupling enables impulse rectification and finite configuration-to-translation exchange, producing bounded relative displacement between system components. When an external momentum sink is present (e.g., frictional contact, tethered structures, or expelled mass), this behavior can result in observable net motion consistent with classical mechanics. In free space, the mechanisms do not produce self-acceleration of a closed system. Repeated operation without external momentum exchange is limited by internal stroke, mass ratios, and geometric constraints, and fully respects conservation of linear momentum and center-of-mass invariance. This addendum supersedes any interpretive language in the earlier preprints that could be construed as implying reactionless propulsion. It constitutes the author’s final statement on the intended scope and physical interpretation of the phase-gated inertial coupling framework.