I think what Justiciar is suggesting is that national ratings would stay under EASA, but only be valid in one particular country.
For example, the IMC rating would simply be an EASA rating, which could be attached to any EASA licence issued by any EASA country, but would only offer privlidges within UK Airspace. I could add an IMC rating to my Irish issued EASA licence, but I could only exercise it within UK FIR's.
Likewise a UK issued EASA licence could add an Altiport rating to it, but again it would only have privlidges within French airspace.
Specific 'local' ratings for on an EASA licence....seems to make sense.
dp