The effect may be very small, but noticeable if the choke adds enough. I know it was noticeable at 5000 rpm.

The fact that it isn't a choke, but an enrichener is why a rider can make a mistake leaving the choke on without any really bad effects. If you did the same with a Honda that has a true choke the bike would eventually be so rich it would barely run. A true choke blocks off part of the throat of the carburetor on the intake side of the throttle slide, just like that in a car. An enrichener is simply an air and fuel circuit that allows enrichening the idle fuel mix through a separate circuit. Nice thing to remember. Another difference is you can easily run a true choke from part open to full closed with ease, an enrichener usually causes a high idle and is not very easy to adjust.

The thing that makes me remember about enricheners is a flat track tuner tuning a two stroke flat tracker had his rider open the enrichener at about 3/4 of the way down the straight. He was fine tuning the oil/gas mix and the fuel/air intake so close to the edge of leanness that he needed that tiny bit of additional fuel/air mix to avoid a seizure and/or burned piston.