The best way to reduce vibration is to buy a device that you can insert into the handlebars that will vibrate with the bike in perfect harmony in the opposing frequency. While this is happening the opposing frequency will cancel out the engine vibrations.
Just let me know if it works. Found this one from Honda! lol
Or just wait till your hands and arms go numb then you wont worry about it.
I have noticed less vibrations with my renthal bars. Also had my bar end weights machined down to fit inside the renthal bars. I dont get numb hands after the riding anymore.