Low compression engine = Low Octane gasoline
If you feel the need to add something, add some Techron fuel system cleaner once a month or so to feel better about using cheap (relatively speaking ) fuel. Stabil also makes an additive for gas with alcohol, it helps neutralize the detrimental effects of the ethanol on internal parts. The biggest problem with ethanol is that it swells rubber parts that aren't made for it and it absorbs water. The water can cause corrosion like rust on steel and oxidation on aluminum. It's primarily for if the engine sits around with fuel in it but also helps even if it's ridden daily.
Increased octane is not only wasted on this motor but also reduces power due to it slowing down the burn rate. You don't get all the available power from a gallon and it just goes out the exhaust. Those still running catalytic converters are at risk of overheating the pipe and surrounding parts due to the fuel being burned in the catalyst rather than the cylinders.
It's a waste of money and fuel.