It's speed! The plane is set-up to handle the left turning tendencies a the most critical speeds at take-off and landing. As you speed up, it's time to neutralize those forces, because now you're going fast!!!!! Now you have to center the rudder trim, or even sometimes go slightly left of center.

The take-off setting for a TBM on the rudder trim has a green-mark on the trim, and a center mark in white. I don't know the exact degree difference, but it takes about 10 seconds of holding the switch to get a full difference between the two.