Hello, I recently acquired a set of open polepiece passive Js to replace my closed type actives, for 5 strings. The pickups work fine, only problem is, the polepieces are radiused, and the radius is less than the one on my bass' neck. Result is the A string sounds a bit louder than the others. I was thinking about sanding down the polepieces for the A string to even out the output. The difference is not that much and a little will go a long way. Is it highly likely that I will make a mess with magnet shrapnel or completely ruin my pickups? They aren't exactly inexpensive. Can I expect a tonal change besides the output reduction, because I will have less polepiece material on? Any thoughts are welcome.