It will only get worse. You might as well change it as soon as possible and get the most benefit from it, or sell the car now with the fault disclosed.
Which Stilo version are we talking about - you mention DMF - is it an Abarth, manual or Selespeed?
I don't know about the JTD but if it's an Abarth, I'd consider re-using the DMF (if you get to it in time, before slipping damages it) or fitting a second-hand DMF (it seems to me they are not that fragile on the 2.4 petrol engine, and you might as well try to keep costs down.)
-Alex