There are two things to revalidate; the aircraft rating and the IR, NOT the CPL. As the ME IR covers SE aircraft there is no reason to revalidate SE and ME IR privileges seperately. You may need to fly a SEP in order to revalidate that Class rating if you do not have 12 hours in the 12 months preceeding expiry in that Class but, there is no point revalidating the IR.
You may revalidate your ME IR in an approved FNPTII provided the last revalidation was conducted in an aeroplane, you cannot do a renewal in a FNPTII, it has to be done in the aircraft.