If you are considering welding the DMF so it no longer has play, DON'T, UNLESS - you change the clutch plate for the spring type found in the solid flywheel.
This will essential convert your DMF to a solid with the welds. Please get your welded flywheel balanced before you refit to avoid the characteristic juddering on idle and high RPM.
Always check the release bearings are in good condition, and if you have the hydraulic release bearing, please install it in the compressed position to avoid failure when re-fitting and bleed it once the gearbox is bolted to the engine.
I have seen people who have replaced their DMF's with solid and then complain about a rumble when the car is idling and the noise goes away when the clutch is pressed. Classic mistake of neglecting a small part in the path of saving money.