The hot-plug matrix's last two cells. H4: unplug from hub port 1.1, replug on 1.2 — per-port identity means the old child is removed and reaped while the new port binds a fresh driver; nothing ties a driver to the old port. H5: three unplug/replug cycles on one port — three reaps, a bind after the last, proving slots, the bus open table, and the manager's driver entries are all reusable across generations.