Second the reaming. I have heard of issues with carbon seatposts on Pista Concepts. They've been known to require reaming due to their ovalized shape as the seattube moves further down. I've also personally experienced and heard about regular Pistas being 27.0 where they were supposed to be 27.2.

Getting the seattube reamed makes sure that it's uniform.

Carbon seatpost failure due to a hairline crack or a forced insertion that weakens it is not a good thing.