Beyond Content: Temporal Structure and Distinct Coupling Regimes in Two Human-LLM Archives

Prior work in this series established that long-form human-LLM interaction can exhibit organized temporal structure (Baldovino, 2026a) and that stateless, surface-matched synthetic baselines do not fully reproduce it (Baldovino, 2026b). The present paper asks whether that organization generalizes across archives by comparing two matched human-LLM archives. Using three paired threads exceeding 600 turns, processed in the same export format and truncated within each pair to a matched length, the analysis compares structural metrics only: turn lengths, rolling variability, amplification, consecutive-turn correlation, and separated user and assistant rolling means. The three pairs support the same higher-order conclusion even where the separating metric profile differs across pairs. What generalizes is not a single shared morphology but the presence of temporally organized long-form regimes whose realization differs across human-coupled archives.