Phase 2's cascade-replica bootstrap does its own full basebackup FROM the new standby_leader (an extra hop beyond Phase 1's legacy-direct copy), so per operator request its window is extended further than Phase 1's — from 1200s (20 min, matched to observed 8-11 min legacy-direct timing) to 2100s (35 min), giving more margin for the additional hop. Phase 1's window is intentionally left unchanged at 1200s since it already has comfortable headroom against the timing we've actually observed for that specific bootstrap path.