octane booster and such are useless in a computer controlled system unless you buy and install a performance chip or computer .you are correct on that but fuel injection cleaners work on deposits and such i have found .All of that stuff is useless in a modern computer-controlled fuel injected auto. Gasoline already has detergents added to the fuel. Never used any of it and and always gotten great fuel mileage and well over 200,000 miles out of my vehicles.
Save that money for gun stuff.