One more thing - you should not reduce rpm at or near full power operations. The reason being, the engine is designed to develop peak pressure from the combustion event once the piston is going away from the cylinder head after reaching top dead center. This way the combustion gives the piston a push. True at least for the engines designed for continuous full power ops.
If you lower RPM at full power, the piston moves towards top dead center slower and if the peak pressure is reached before or close to top dead center, you end up pushing the piston down when its trying to move up. This is not productive towards moving your crankshaft and causes a lot of energy to be absorbed by the cylinder head which shows up as high CHT. Temperature is after all average velocity of the molecules, which in turn is dependent how much energy you have fed those molecules.
If your CHTs are 380 or less, i guess you are fine, but you are probably doing wasted work by not developing peak pressure at the correct time.
If you want to know more, search for a yhread titled "turbo lop" here. I know yours is not turbo, but the thread has a bunch of very interesting articles that explain what I am talking about