Fuel cell EPS ratings use the maker's derating factors (altitude, ambient, fuel energy content, accessory losses, site) to judge whether connected load is met; controls and power conditioning hold frequency within a band suited to the load at steady state, with droop and the dip on one-step full load inside the load's range and recovery as the load requires. Later 5.7 clauses (starting equipment per the maker's instructions and further accessories) are in the edition but only partly held.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.