yes you can loosen and tighten however you want. Basically if you are looking at the pickup the screws closest to the bridge side when raised will increase high end response and general tightness. The set of screws closest to the neck when raised will fatten the tone and reduce brightness, it'll probably sound a little looser. So you can custom set each strings response. I raise about 1/2-1 turn the bridge side pole under my lowest 2 strings to tighten their bass response and add attack. Under my 2 unwound highest strings I do the opposite and raise the neck side pole pieces to fatten them up and give them a slightly warmer less trebly response. So when looking at each string there is 2 pole pieces beneath each one and those 2 effect that strings tone. So remember when raising closer to the bridge adds high end and attack, and closer to the neck adds warmth and fattness.
Also, this might be subtle so don't expect it to sound like a whole new guitar. In mine I hear the change very easily. Hope this helps.
