I have this rim laying in my room now, which I have grinded moooore than 25 times, both light and harsch. By looking at it now, I can say that it will take a hell of a lot more grinds.
If I where you, I'd get rid of that booster, grind the rim, order a pair of Rockman CNC blues, set the pads up so they hit hit the rim perfect (Meaning that the whole pad hits the rim at the same time) and go out and ride