Ignition timing is adjusted (for all fuel types) such that the engine will (just) not knock.

Made-in-Jap: knock sensors are meant for adapting to octane rate: if the ECU would correct for every little ping identified by the knock sensors under heavy load, this would result in a severe performance degradation. Again: the ECU withh input from the knock sensors will adapt ignition timing to octane rate and that is done under normal driving conditions, not spefically under heavy load. Ignition timing variation etc for various driving conditions (flat vs laod)is set by the ECU with input from throttle position, rpm, etc.