I'm not sure what they meant by that but it makes no sense whatsoever. I've tried all sorts of fuel brands and blends. You may have to adjust the needle a little when switching but that's it. It doesn't change anything inside the engine.

For your .46-AX, it really likes regular old 10%. It will run well on 15% too but that just costs more in my opinion. I even run OS 4-strokes on 10% Cool Power. People say you need at least 20% to make it idle and all sorts of other stuff but mine run just fine for general sport flying. I may switch to 15% on the 4-strokes but only if I see a real performance difference.