The best fuel additives are octane boosters and fuel conditioners. They are chelated.
There are two I know of. One is Torco Accelerator and the other I can’t remember.
I’ve used the Torco in a ton of different stuff, including my dirt bikes. They condition the fuel and help burn all the extra junk that is in pump fuel. You can see how much cleaner they burn by the exhaust ports and the exhaust itself.