[Flyman 27]

The only work that should be done to the flywheel is a mild application of scotchbright pads. You do NOT want to "resurface" a dual mass flywheel.
The little shavings can easily get into the working parts of the flywheel and then it is a boat anchor.
About 18 months ago I was going to Mark's to swap my clutch. The flywheel had been "resurfaced" and there were chips in the mechanism, which was evident by turning the wheel & hearing the grinding of little chips.
Mark said this was common in flywheels that had been machined.
I had 2 flywheels that were bad for this reason.
I ended up using an old rusty flywheel from a friend (thanks Paul!). It cleaned up nicely with a little scotchbright.