There's nothing to fix with the dual-mass flywheel. It's there to absorb the "piston pounding" from the engine.
If you switch out your flywheel to a single-mass, there will no longer be anything to absorb the engine vibrations, and you'll hear it throughout the rest of your drivetrain (assuming you go lightweight). If you get a steel flywheel, the weight of it will likely dampen the engine vibrations. Yes, the notorious deceleration vibration will completely disappear, but you'll likely get other sounds in its place.
2014 GT Coupe, 3.73 gears, Security Pkg