Welcome aboard!
If the trigger is lighter than their standards which is somewhere in the 3-3½lbs range, they may replace parts to get it back to within their standards.
As Doug said, when they fit barrels, they don't make changes to the frame, just the barrel being fitted, so the only change that will affect accuracy when you swap barrels will be the forend screw torque and/or any changes you make in the forend to get the new barrel to shoot well. Many members order a forend for each accessory barrel so it's dedicated to that barrel to eliminate that issue.
Tim