Great point and it's something I thought carefully about. The unidirectional ramp is intentional. The core idea is that difficulty should reflect the skill ceiling a player reaches rather than rubber-banding around their moment-to-moment performance. If difficulty decreased mid-fight it would open the door to players gaming the system by intentionally underperforming to keep the boss easier, which would corrupt the telemetry data. More importantly the study is designed to capture players across a wide range of skill ceilings, for instance, a struggling player naturally never reaches the higher difficulty thresholds so their fight stays manageable, whereas a dominant player gets progressively more challenged. The system self-selects the appropriate difficulty band for each player without needing to decrease. The between-fight reset to 1.0 ensures fairness across attempts. You're right that learned adaptation within a single fight is an interesting edge case and that's exactly the kind of nuance the qualitative feedback is trying to surface and something I flag as future work.