I would NOT recommend filing anything on it - just a few strokes at the wrong angle will render it unsafe. A very light polishing of the sear surfaces shouldn't hurt if you know what you're doing.
I have several AT Savages and they all have improved somewhat after 1-200 rounds. Shooting a new trigger has the effect of polishing the mating sear surfaces and you may even start noticing a difference at 50 rounds.
IIRC, there are also at least two different springs for those triggers - one that is supposed to allow a minimum pull of 2.5 lbs and another that allows a minimum of 1.5 lbs. They are color coded and I don't remember which is which, but if you have the heavier spring you should be able to replace it with a lighter one. You might try googling SharpShooterSupply and see if they have the springs.