Dar, I doubt that the throttle setting Cyclic is talking about (the setting that is less than full throttle where rpm is at or close to peak) is greatly influenced by the low speed needle.

As for the onloading factor, that is a valid observation and as you say could affect performance where maximum speed is desired. The application I am tuning this 2300 for is a Funtana 90. The owner only uses full throttle on his vertical uplines so there should be very little unloading in normal flight.