The method of processing this varies between countries. Many EASA States simply limit the privileges until the holder has met the experience requirements then they are automatically lifted wheras the CAA treats it like the old AFI/FI transition where they re-issue the certificate. Perhaps the UK removal of the limitation will be the most onerous but then its a case of will EASA accept non EASA G Reg aircraft and vice versa. Nobody will apply the common sense approach of why we do this in the first place!