The dual mass flywheel can play a role. But it would be the last thing I would blame for the main problem of the ref hang. After I got the program update for my 2008 3.0 Roadster Series 2 in 2009, the engine was like transformed. Also a certain inherent inertia was gone. I had always blamed the dual mass flywheel for this inertia before the update.
Another case concerning the flywheel: On my current 4/4 the ECU program switch under the brake pedal was broken. Before I got a new switch, I had driven with the always open circuit, so I could drive again at all. Without the switch, which is only activated when braking (only then closed circuit), the engine turns back much slower and slower. Probably to meet Euro 5 and to burn residual fuel or gases. I bet if you compare these two program settings, 80% of the observers would have said that there is a lighter flywheel in the program setting for braking.
