RTmount State Retention and Representation Fidelity Across Update, Filesystem, and Recovery Boundaries

RTmount presents a retrospective synthesis of a longitudinal investigation into state retention, representation-dependent behavior, and recovery failure across software-update, filesystem, device-identity, and recovery boundaries. Drawing on preserved evidence spanning August 2025 through September 2026, the study examines OTA and NVRAM state handling, MobileSoftwareUpdate/UpdateBrain processing, APFS snapshot and remount operations, pairing and identity observations, and later recovery-bound behavior. It introduces the Read–Write–Remount (RWR) model to distinguish provider representation, retained or reconstructed state, local transformation, and downstream observation, and identifies four unresolved causal relations for further experimental discrimination. The work emphasizes source traceability, contradictory and negative evidence, explicit non-claims, and separation between observed behavior and retrospective causal interpretation. RTmount provides a bounded hypothesis and experimental framework rather than a demonstrated exploit chain; it does not establish ROM modification, a persistence-causing UpdateBrain rewrite, vulnerability identity, researcher attribution, or a direct causal relationship between the separately studied EXR representation behavior and the later APFS/recovery outcome.