Expand the DisAgg role-change page's step-down section with the motivation for planned asynchronous demotion and its advantages over blocking or crash/replay approaches. Cover the API sequence, cutoff/checkpoint boundary, transaction routing and straddler retries, mirrored writes and stable-first ordering, reader/cursor behavior, schema epochs, and handle demotion. Explain application requirements, their rationale, supported-operation restrictions, and key performance costs and statistics. Describe the current implementation; defer formal concurrency analysis to the follow-up ticket.