I have always advocated an uprated clutch right from the start.
IIRC the std is about 300ft/lbs, however there have been many in the past with 280ft/lbs 'soft maps' and driving away from well respected mappers on here with clutch slip on the day.
Clutches are not an exact science and you will always in my opinion run a high risk of slippage even on a soft map. Conversely there are those that have not had that
problem although from experience off this site, they tend to be in the minority.
I have been running a PD150 for nearly 12 years now, 9 of which has been on an uprated clutch and enjoying 330ft/lbs of torque during that time.
If you are going to keep the car for a few years I would do it properly otherwise I wouldn't bother as potentially it could cost you and would easily equate to a new uprated clutch together with a half fat map should it all go horribly wrong. Do you then get it mapped again for a full map?