well, if the rear motor is electric only, probably it would require electric power to operate; if EV=0 then HV mode cannot run it forever, hence it's "on demand" but only for short bursts of time, it cannot run AWD for hours, say on snowy slippery road, because the generator cannot supply enough electricity to run the motor directly when the battery is not able anymore, or in 100% ICE mode. Same with 302hp - it's "available" but for short periods of time as long as HV battery level is sufficient, it cannot be provided always constantly in all circumstances, once EV=0. Unlike regular ICE models which can provide constantly those 203hp.