The first question here is do you hold an EASA licence? If so why do you need to have a licence issued, as it is valid for life? Only the ratings in it have to be revalidated or renewed.
As you refer to revalidation I must assume you have a licence and that the CAA rather than the Examiner conducts the revalidation process. There is no requirement to relate the ME IR to a Class rating except that if conducted in a single it would be limited to SE.
You cannot revalidate the MEP in a FNPT, only an aeroplane or a Flt Sim that replicates the aeroplane of which there are none for the MEP Class. You refer to an LPC rathan an IR Prof Check! Put simply you can revalidate the IR in the FNPT, but not the Class rating.