exactly, ron is merely the fuels resistance to pre ignition... the calorific value is "usually" lower so if you dont change your ign settings it will lose you power and thermal efficiency from less engery transfer and also with a slower burn due to its ron "could" result in even more lost power as the peak cylinder pressue maybe pushed past the best point for torque... and keeping heat so late in the cycle can burn valves out.
but thats all theory and my personal views... which lets face it are cRaZy lmao