Can you take a photo or describe which of the screws your referring to? I've tinkered with the Quattro and can't wrap my mind around why a screw would be backed out so far.
I just re-read Kirk's post and I believe he has it spot on about which screw does what. He left the one that's closest in front of the trigger alone, that's the one I had backed out. I believe it shortens the length of the preliminary travel of the trigger if you back it out.